B-cell reduction using cd37-specific and cd20-specific binding molecules

ABSTRACT

The present invention generally provides methods for B-cell reduction in an individual using CD37-specific binding molecules. In particular, the invention provides methods for B-cell reduction using CD37-specific binding molecules alone, or a combination of CD37-specific binding molecules and CD20-specific binding molecules, in some instances a synergistic combination. The invention further provides materials and methods for treatment of diseases involving aberrant B-cell activity. In addition, the invention provides humanized CD37-specific binding molecules.

The present application is a continuation of U.S. application Ser. No.11/493,132, filed Jul. 25, 2005, which claims benefit under 35 U.S.C.§119 of U.S. Patent Application No. 60/702,499, which was filed Jul. 25,2005, Unites States Patent Application No. 60/798,344, which was filedMay 16, 2006, each of which is incorporated herein by reference in itsentirety.

STATEMENT REGARDING SEQUENCE LISTING

The Sequence Listing associated with this application is provided intext format in lieu of a paper copy, and is hereby incorporated byreference into the specification. The name of the text file containingthe Sequence Listing is EMER_(—)012_(—)03US_SubSeqList_ST25.txt. Thetext file is 228 KB, was created on Apr. 12, 2013, and is beingsubmitted electronically via EFS-Web.

FIELD OF THE INVENTION

The present invention generally provides methods for B-cell reduction inan individual using CD37-specific binding molecules. In particular, theinvention provides methods for B-cell reduction using CD37-specificbinding molecules alone, or a combination of CD37-specific bindingmolecules and CD20-specific binding molecules, in some instances asynergistic combination. The invention further provides materials andmethods for treatment of diseases involving aberrant B-cell activity.

BACKGROUND OF THE INVENTION

In its usual role, the human immune system protects the body from damagefrom foreign substances and pathogens. One way in which the immunesystem protects the body is by production of specialized cells called Blymphocytes or B-cells. B-cells produce antibodies that bind to, and insome cases mediate destruction of, a foreign substance or pathogen.

In some instances though, the human immune system and specifically the Blymphocytes of the human immune system go awry and disease results.There are numerous cancers that involve uncontrolled proliferation ofB-cells. There are also numerous autoimmune diseases that involve B-cellproduction of antibodies that, instead of binding to foreign substancesand pathogens, bind to parts of the body. Such antibodies are sometimescalled autoantibodies. In addition, there are numerous autoimmune andinflammatory diseases that involve B-cells in their pathology, forexample, through inappropriate B-cell antigen presentation to T-cells,or through other pathways involving B-cells. For example,autoimmune-prone mice deficient in B-cells do not develop autoimmunekidney disease, vasculitis or autoantibodies. See Shlomchik et al., JExp. Med., 180:1295-306 (1994). Interestingly, these sameautoimmune-prone mice which possess B-cells but are deficient inimmunoglobulin production, do develop autoimmune diseases when inducedexperimentally as described by Chan et al., J Exp. Med., 189:1639-48(1999), indicating that B-cells play an integral role in development ofautoimmune disease.

B-cells can be identified by molecules on their cell surface. CD20 wasthe first human B-cell lineage-specific surface molecule identified by amonoclonal antibody. It is a non-glycosylated, hydrophobic 35 kDa B-celltransmembrane phosphoprotein that has both its amino and carboxy endssituated inside the cell. See, Einfeld et al., EMBO J., 7:711-17 (1998).CD20 is expressed by all normal mature B-cells, but is not expressed byprecursor B-cells or plasma cells. Natural ligands for CD20 have notbeen identified, and the function of CD20 in B-cell biology is stillincompletely understood.

Another B-cell lineage-specific cell surface molecule is CD37. CD37 is aheavily glycosylated 40-52 kDa protein that belongs to the tetraspanintransmembrane family of cell surface antigens. It traverses the cellmembrane four times forming two extracellular loops and exposing itsamino and carboxy ends to the cytoplasm. CD37 is highly expressed onnormal antibody-producing (sIg+)B-cells, but is not expressed onpre-B-cells or plasma cells. The expression of CD37 on resting andactivated T cells, monocytes and granulocytes is low and there is nodetectable CD37 expression on NK cells, platelets or erythrocytes. See,Belov et al., Cancer Res., 61(11):4483-4489 (2001); Schwartz-Albiez etal., J. Immunol., 140(3): 905-914 (1988); and Link et al., J. Immunol.,137(9): 3013-3018 (1988). Besides normal B-cells, almost allmalignancies of B-cell origin are positive for CD37 expression,including CLL, NHL, and hairy cell leukemia [Moore et al., Journal ofPathology, 152: 13-21 (1987); Merson and Brochier, Immunology Letters,19: 269-272 (1988); and Faure et al., American Journal ofDermatopathology, 12 (3): 122-133 (1990)]. CD37 participates inregulation of B-cell function, since mice lacking CD37 were found tohave low levels of serum IgG1 and to be impaired in their humoralresponse to viral antigens and model antigens. It appears to act as anonclassical costimulatory molecule or by directly influencing antigenpresentation via complex formation with MHC class II molecules. SeeKnobeloch et al., Mol. Cell. Biol., 20(15):5363-5369 (2000). CD37 alsoseems to play a role in TCR signaling. See Van Spriel et al., J.Immunol., 172: 2953-2961 (2004).

Research and drug development has occurred based on the concept thatB-cell lineage-specific cell surface molecules such as CD37 or CD20 canthemselves be targets for antibodies that would bind to, and mediatedestruction of, cancerous and autoimmune disease-causing B-cells thathave CD37 or CD20 on their surfaces. Termed “immunotherapy,” antibodiesmade (or based on antibodies made) in a non-human animal that bind toCD37 or CD20 were given to a patient to deplete cancerous or autoimmunedisease-causing B-cells.

One antibody to CD37 has been labeled with ¹³¹I and tested in clinicaltrials for therapy of NHL. See Press et al., J. Clin. Oncol., 7(3):1027-1038 (1989); Bernstein et al., Cancer Res. (Suppl.), 50: 1017-1021(1990); Press et al., Front. Radiat. Ther. Oncol., 24: 204-213 (1990);Press et al., Adv. Exp. Med. Biol., 303: 91-96 (1991) and Brown et al.,Nucl. Med. Biol., 24: 657-663 (1997). The antibody, MB-1, is a marineIgG1 monoclonal antibody that lacks Fc effector functions such asantibody-dependent cellular cytotoxicity (ADCC) and MB-1 did not inhibittumor growth in an in vivo xenograft model unless it had been labeledwith an isotope (Buchsbaum et al., Cancer Res., 52(83): 6476-6481(1992). Favorable biodistribution of ¹³¹I-MB-1 was seen in lymphomapatients who had lower tumor burdens (<1 kg) and therapy of thesepatients resulted in complete tumor remissions lasting from 4 to 11months (Press et al., 1989 and Bernstein et al. 1990).

In addition, an immunoconjugate composed of the drug adriamycin linkedto G28-1, another anti-CD37 antibody, has been evaluated in mice andshowed effects through internalization and intracellular release of thedrug. See Braslawsky et al., Cancer Immunol. Immunother., 33(6): 367-374(1991).

Various groups have investigated the use of anti-CD20 antibodies totreat B-cell related diseases. One treatment consists of anti-CD20antibodies prepared in the form of radionuclides for treating B-celllymphoma (e.g., ¹³¹I-labeled anti-CD20 antibody), as well as a⁸⁹Sr-labeled form for the palliation of bone pain caused by prostate andbreast cancer metastases [Endo, Gan To Kagaku Ryoho, 26: 744-748(1999)].

Another group developed a chimeric monoclonal antibody specific forCD20, consisting of heavy and light chain variable regions of mouseorigin fused to human IgG1 heavy chain and human kappa light chainconstant regions. The chimeric antibody reportedly retained the abilityto bind to CD20 and the ability to mediate ADCC and to fix complement.See, Liu et al., J. Immunol. 139:3521-26 (1987). Yet another chimericanti-CD20 antibody was made from IDEC hybridoma C2B8 and was namedrituximab. The mechanism of anti-tumor activity of rituximab is thoughtto be a combination of several activities, including ADCC, complementfixation, and triggering of signals that promote apoptosis in malignantB-cells, although the large size of the chimeric antibody preventsoptimal diffusion of the molecule into lymphoid tissues that containmalignant B-cells, thereby limiting its anti-tumor activities. ADCC is acell-mediated reaction in which nonspecific cytotoxic cells that expressFc receptors (FcRs) (e.g. Natural Killer (NK) cells, neutrophils, andmacrophages) recognize bound antibody on a target cell and subsequentlycause lysis of the target cell. Complement fixation, orcomplement-dependent cytotoxicity (CDC) is the ability of a molecule tolyse a target in the presence of complement. The complement activationpathway is initiated by the binding of the first component of thecomplement system (C1q) to a molecule (e.g. an antibody) complexed witha cognate antigen. The large size of rituximab prevents optimaldiffusion of the molecule into lymphoid tissues that contain malignantB-cells, thereby limiting these anti-tumor activities.

Rituximab, typically administered in 4 weekly infusions, is currentlyused to treat low-grade or follicular B-cell non-Hodgkin's lymphoma[McLaughlin at al., Oncology, 12: 1763-1777 (1998); Leget et al., Curr.Opin, Oncol., 10: 548-551 (1998)] and in relapsed stage III/IVfollicular lymphoma [White et al., Pharm. Sci. Technol. Today, 2: 95-101(1999)]. Other disorders treatable with rituximab include follicularcentre cell lymphoma (FCC), mantle cell lymphoma (MCL), diffuse largecell lymphoma (DLCL), and small lymphocytic lymphoma (SLL) [Nguyen etal., Eur J Haematol., 62:76-82 (1999)]. Rituximab administered in weeklyinfusions is also used to treat CLL [Lin et al., Sem Oncol., 30:483-92(2003)].

Anti-CD20 antibodies have also been used to treat patients sufferingfrom autoimmune diseases associated with B-cell production ofautoantibodies. For example, rituximab has demonstrated significantclinical benefit in depleting CD20+ B-cells in patients with multipleautoimmune/inflammatory diseases including RA [Edwards, N Engl J. Med.,350:2546-2548 (2004); Cambridge et al., Arthritis Rheum., 48:2146-54(2003)]. RA patients received continued doses of methotrexate (MTX) anda 4 dose course of rituximab infusion (Edwards, supra). These patientsshowed improved American College of Rheumatology (ACR) responsescompared to control groups.

In a trial for the treatment of systemic lupus erythematosus (SLE)[Leandro et al., Arthritis Rheum., 46:2673-2677 (2002)], patients wereadministered two infusions of high dose rituximab, and demonstratedB-cell reduction and improved disease state. In a second study of B-cellreduction in SLE [Looney at al., Arthritis Rheum., 50:2580-2589 (2004)],patients were given a single infusion of 100 mg/m2 (low dose), a singleinfusion of 375 mg/m2 (intermediate dose), or as 4 infusions (1 weekapart) of 375 mg/m2 (high dose) rituximab. These patients demonstratedB-cell reduction and improved disease scores, but the treatment did notalter the level of autoantibody. Trials of rituximab have also beencarried out in Waldenstrom's macroglobulinemia [Treon at al.,Immunother., 24:272-279 (2000)], where patients showed increasedhematocrit (HCT) and platelet (PLT) counts after 4 infusions ofrituximab.

Recent reports of rituximab treatment in patients suffering frommultiple sclerosis, an autoimmune disease affecting the central nervoussystem, indicate that a course of treatment depletes peripheral B-cellsbut has little effect on B-cells in cerebrospinal fluid. See Monson etal., Arch. Neural., 62: 258-264 (2005).

Additional publications concerning the use of rituximab include: Stashiet al. “Rituximab chimeric anti-CD20 monoclonal antibody treatment foradults with chronic idiopathic thrombocytopenic purpura” Blood98:952-957 (2001); Matthews, R. “Medical Heretics” New Scientist (7 Apr.2001); Leandro at al. “Clinical outcome in 22 patients with rheumatoidarthritis treated with B lymphocyte depletion” Ann Rheum Dis 61:833-888(2002); Leandro et al. “Lymphocyte depletion in rheumatoid arthritis:early evidence for safety, efficacy and dose response. Arthritis andRheumatism 44(9): S370 (2001); Leandro et al. “An open study of Blymphocyte depletion in systemic lupus erythematosus”, Arthritis Rheum.46:2673-2677 (2002); Edwards et al., “Sustained improvement inrheumatoid arthritis following a protocol designed to deplete Blymphocytes” Rheumatology 40:205-211 (2001); Edwards et al.“B-lymphocyte depletion therapy in rheumatoid arthritis and otherautoimmune disorders” Biochem. Soc. Trans. 30(4):824-828 (2002); Edwardset al. “Efficacy and safety of rituximab, a B-cell targeted chimericmonoclonal antibody: A randomized, placebo controlled trial in patientswith rheumatoid arthritis. Arthritis Rheum. 46: S197 (2002); Levine etal., “1 gM antibody-related polyneuropathies: B-cell depletionchemotherapy using rituximab” Neurology 52: 1701-1704 (1999); DeVita etal. “Efficacy of selective B-cell blockade in the treatment ofrheumatoid arthritis” Arthritis Rheum 46:2029-2033 (2002); Hidashida etal. “Treatment of DMARD-Refractory rheumatoid arthritis with rituximab.”Presented at the Annual Scientific Meeting of the American College ofRheumatology; October 24-29; New Orleans, La. 2002; Tuscano, J.“Successful treatment of Infliximab-refractory rheumatoid arthritis withrituximab” Presented at the Annual Scientific Meeting of the AmericanCollege of Rheumatology; October 24-29; New Orleans, La. 2002.

Problems associated with rituximab therapy remain. For example, themajority of cancer patients treated with rituximab relapse, generallywithin about 6-12 months, and fatal infusion reactions within 24 hoursof rituximab infusion have been reported. These fatal reactions followedan infusion reaction complex that included hypoxia, pulmonaryinfiltrates, acute respiratory distress syndrome, myocardial infarction,ventricular fibrillation or cardiogenic shock. Acute renal failurerequiring dialysis with instances of fatal outcome has also beenreported in the setting of tumor lysis syndrome following treatment withrituximab, as have severe mucocutaneous reactions, some with fataloutcome. Additionally, high doses of rituximab are required forintravenous injection because the molecule is large, approximately 150kDa, and, as noted above, diffusion into the lymphoid tissues where manytumor cells reside is limited.

Because normal mature B-cells also express CD37 and CD20, normal B-cellsare depleted by anti-CD37 (Press et al., 1989) or anti-CD20 antibodytherapy [Reff et al., Blood 83:435-445 (1994)]. After treatment iscompleted, however, normal B-cells can be regenerated from CD37- andCD20-negative B-cell precursors; therefore, patients treated withanti-CD37 or anti-CD20 therapy do not experience significantimmunosuppression.

Monoclonal antibody technology and genetic engineering methods have ledto development of immunoglobulin molecules for diagnosis and treatmentof human diseases. Protein engineering has been applied to improve theaffinity of an antibody for its cognate antigen, to diminish problemsrelated to immunogenicity, and to alter an antibody's effectorfunctions. The domain structure of immunoglobulins is amenable toengineering, in that the antigen binding domains and the domainsconferring effector functions may be exchanged between immunoglobulinclasses and subclasses. Immunoglobulin structure and function arereviewed, for example, in Harlow et al., Eds., Antibodies: A LaboratoryManual, Chapter 14, Cold Spring Harbor Laboratory, Cold Spring Harbor(1988). An extensive introduction as well as detailed information aboutall aspects of recombinant antibody technology can be found in thetextbook “Recombinant Antibodies” (John Wiley & Sons, NY, 1999). Acomprehensive collection of detailed antibody engineering lab Protocolscan be found in R. Kontermann and S. Dubel (eds.), “The AntibodyEngineering Lab Manual” (Springer Verlag, Heidelberg/New York, 2000).

Recently, smaller immunoglobulin molecules have been constructed toovercome problems associated with whole immunoglobulin therapy. Singlechain Fv (scFv) comprise an antibody heavy chain variable domain joinedvia a short linker peptide to an antibody light chain variable domain[Huston et al., Proc. Natl. Aced. Sci. USA, 85: 5879-5883 (1988)]. Inaddition to variable regions, each of the antibody chains has one ormore constant regions. Light chains have a single constant regiondomain. Thus, light chains have one variable region and one constantregion. Heavy chains have several constant region domains. The heavychains in IgG, IgA, and IgD antibodies have three constant regiondomains, which are designated CH1, CH2, and CH3, and the heavy chains inIgM and IgE antibodies have four constant region domains, CH1, CH2, CH3and CH4. Thus, heavy chains have one variable region and three or fourconstant regions.

The heavy chains of immunoglobulins can also be divided into threefunctional regions: the Fd region (a fragment comprising V.sub.H andCH1, i.e., the two N-terminal domains of the heavy chain), the hingeregion, and the Fc region (the “fragment crystallizable” region, derivedfrom constant regions and formed after pepsin digestion). The Fd regionin combination with the light chain forms an Fab (the “fragmentantigen-binding”). Because an antigen will react stereochemically withthe antigen-binding region at the amino terminus of each Fab the IgGmolecule is divalent, i.e., it can bind to two antigen molecules. The Fccontains the domains that interact with immunoglobulin receptors oncells and with the initial elements of the complement cascade. Thus, theFc fragment is generally considered responsible for the effectorfunctions of an immunoglobulin, such as complement fixation and bindingto Fc receptors.

Because of the small size of scFv molecules, they exhibit very rapidclearance from plasma and tissues and more effective penetration intotissues than whole immunoglobulin. An anti-tumor scFv showed more rapidtumor penetration and more even distribution through the tumor mass thanthe corresponding chimeric antibody [Yokota et al., Cancer Res., 52,3402-3408 (1992)]. Fusion of an scFv to another molecule, such as atoxin, takes advantage of the specific antigen-binding activity and thesmall size of an scFv to deliver the toxin to a target tissue. [Chaudaryet al., Nature, 339:394 (1989); Batra et al., Mol. Cell. Biol., 11:2200(1991)].

Despite the advantages of scFv molecules, several drawbacks to their useexist. While rapid clearance of scFv may reduce toxic effects in normalcells, such rapid clearance may prevent delivery of a minimum effectivedose to the target tissue. Manufacturing adequate amounts of scFv foradministration to patients has been challenging due to difficulties inexpression and isolation of scFv that adversely affect the yield. Duringexpression, scFv molecules lack stability and often aggregate due topairing of variable regions from different molecules. Furthermore,production levels of scFv molecules in mammalian expression systems arelow, limiting the potential for efficient manufacturing of scFvmolecules for therapy [Davis et al, J Biol. Chem., 265:10410-10418(1990); Traunecker et al., EMBO J, 10: 3655-3659 (1991). Strategies forimproving production have been explored, including addition ofglycosylation sites to the variable regions [Jost, C. R. U.S. Pat. No.5,888,773, Jost et al, J. Biol. Chem., 69: 26267-26273 (1994)].

Another disadvantage to using scFv for therapy is the lack of effectorfunction. An scFv without the cytolytic functions, ADCC and complementdependent-cytotoxicity (CDC), associated with the constant region of animmunoglobulin may be ineffective for treating disease. Even thoughdevelopment of scFv technology began over 12 years ago, currently noscFv products are approved for therapy.

Alternatively, it has been proposed that fusion of an scFv to anothermolecule, such as a toxin, could take advantage of the specificantigen-binding activity and the small size of an scFv to deliver thetoxin to a target tissue. Chaudary et al., Nature 339:394 (1989); Batraet al., Mol. Cell. Biol. 11:2200 (1991). Conjugation or fusion of toxinsto scFvs has thus been offered as an alternative strategy to providepotent, antigen-specific molecules, but dosing with such conjugates orchimeras can be limited by excessive and/or non-specific toxicity due tothe toxin moiety of such preparations. Toxic effects may includesupraphysiological elevation of liver enzymes and vascular leaksyndrome, and other undesired effects. In addition, immunotoxins arethemselves highly immunogenic upon administration to a host, and hostantibodies generated against the immunotoxin limit potential usefulnessfor repeated therapeutic treatments of an individual.

Other engineered fusion proteins, termed small, modularimmunopharmaceutical (SMIP™) products, are described in co-owned USPatent Publications 2003/133939, 2003/0118592, and 2005/0136049, andco-owned International Patent Publications WO02/056910, WO2005/037989.,and WO2005/017148, which are all incorporated by reference herein. SMIPproducts are novel binding domain-immunoglobulin fusion proteins thatfeature a binding domain for a cognate structure such as an antigen, acounterreceptor or the like; an IgG1, IGA or IgE hinge regionpolypeptide or a mutant IgG1 hinge region polypeptide having eitherzero, one or two cysteine residues; and immunoglobulin CH2 and CH3domains. SMIP products are capable of ADCC and/or CDC.

Although there has been extensive research carried out on antibody-basedtherapies, there remains a need in the art for improved methods to treatdiseases associated with aberrant B-cell activity. The methods of thepresent invention described and claimed herein provide such improvedmethods as well as other advantages.

SUMMARY OF THE INVENTION

The present invention provides methods for reducing B-cells usingCD37-specific binding molecules. In some methods of the invention, useof combinations of CD37-specific binding molecules (one or moreCD37-specific binding molecules) and CD20-specific binding molecules(one or more CD20-specific binding molecules) results in increasedB-cell reduction. In some of these methods, the combinations aresynergistic. In a related aspect, the invention provides a method oftreating an individual having, or suspected of having, a diseaseassociated with aberrant B-cell activity.

The present invention also provides humanized CD37-specific bindingmolecules (e.g., humanized TRU-016 constructs) and methods for reducingB-cells using these molecules. In some embodiments of the methods of theinvention, uses of combinations of humanized TRU-016 constructs with oneor more CD20-specific binding molecules is contemplated. In anotheraspect, the invention provides methods of treating individuals having,or suspected of having, a disease associated with aberrant B-cellactivity. Related aspects of the invention are drawn to methods ofpreventing any such disease and methods of ameliorating a symptomassociated with such a disease comprising administering a dose of ahumanized CD37-specific binding molecule effective to treat or preventsuch disease, or to ameliorate a symptom of such disease.

“Aberrant B-cell activity” refers to B-cell activity that deviates fromthe normal, proper, or expected course. For example, aberrant. B-cellactivity may include inappropriate proliferation of cells whose DNA orother cellular components have become damaged or defective. AberrantB-cell activity may include cell proliferation whose characteristics areassociated with a disease caused by, mediated by, or resulting ininappropriately high levels of cell division, inappropriately low levelsof apoptosis, or both. Such diseases may be characterized, for example,by single or multiple local abnormal proliferations of cells, groups ofcells or tissue(s), whether cancerous or non-cancerous, benign ormalignant. Aberrant B-cell activity may also include aberrant antibodyproduction, such as production of autoantibodies, or overproduction ofantibodies typically desirable when produced at normal levels. It iscontemplated that aberrant B-cell activity may occur in certainsubpopulations of B-cells and not in other subpopulations. AberrantB-cell activity may also include inappropriate stimulation of T-cells,such as by inappropriate B-cell antigen presentation to T-cells or byother pathways involving B-cells.

“Treatment” or “treating” refers to either a therapeutic treatment orprophylactic/preventative treatment. A therapeutic treatment may improveat least one symptom of disease in an individual receiving treatment ormay delay worsening of a progressive disease in an individual, orprevent onset of additional associated diseases.

A “therapeutically effective dose” or “effective dose” of aCD20-specific binding molecule refers to that amount of the compoundsufficient to result in amelioration of one or more symptoms of thedisease being treated. When applied to an individual active ingredient,administered alone, a therapeutically effective dose refers to thatingredient alone. When applied to a combination, a therapeuticallyeffective dose refers to combined amounts of the active ingredients thatresult in the therapeutic effect, whether administered serially orsimultaneously. The invention specifically contemplates that one or morespecific binding molecules may be administered according to methods ofthe invention, each in an effective dose.

“An individual having, or suspected of having, a disease associated withaberrant B-cell activity” is an individual in whom a disease or asymptom of a disorder may be caused by aberrant B-cell activity, may beexacerbated by aberrant B-cell activity, or may be relieved byregulation of B-cell activity. Examples of such diseases are a B-cellcancer (for example, B-cell lymphoma, a B-cell leukemia or a B-cellmyeloma), a disease characterized by autoantibody production or adisease characterized by inappropriate T-cell stimulation caused byinappropriate B-cell antigen presentation to T-cells or caused by otherpathways involving B-cells.

In one exemplary aspect, an individual treated by methods of theinvention demonstrates a response to treatment that is better than, orimproved relative to, the response to treatment with rituximab. Aresponse which is improved over treatment with rituximab refers to aclinical response wherein treatment by a method of the invention resultsin a clinical response in a patient that is better than a clinicalresponse in a patient receiving rituximab therapy, such as rituximab. Animproved response is assessed by comparison of clinical criteriawell-known in the art and described herein. Exemplary criteria include,but are not limited to, duration of B cell depletion, reduction in Bcell numbers overall, reduction in B cell numbers in a biologicalsample, reduction in tumor size, reduction in the number of tumors,existing and/or appearing after treatment, and improved overall responseas assessed by patients themselves and physicians, e.g., using anInternational Prognostic Index. The improvement may be in one or morethan one of the clinical criteria. An improved response with the methodof the invention may be due to an inadequate response to previous orcurrent treatment with rituximab, for example, because of toxicityand/or inadequate efficacy of the rituximab treatment.

B-cell cancers include B-cell lymphomas [such as various forms ofHodgkin's disease, non-Hodgkins lymphoma (NHL) or central nervous systemlymphomas], leukemias [such as acute lymphoblastic leukemia (ALL),chronic lymphocytic leukemia (CLL), Hairy cell leukemia and chronicmyoblastic leukemia] and myelomas (such as multiple myeloma). AdditionalB cell cancers include small lymphocytic lymphoma, B-cell prolymphocyticleukemia, lymphoplasmacytic lymphoma, splenic marginal zone lymphoma,plasma cell myeloma, solitary plasmacytoma of bone, extraosseousplasmacytoma, extra-nodal marginal zone B-cell lymphoma ofmucosa-associated (MALT) lymphoid tissue, nodal marginal zone B-celllymphoma, follicular lymphoma, mantle cell lymphoma, diffuse largeB-cell lymphoma, mediastinal (thymic) large B-cell lymphoma,intravascular large B-cell lymphoma, primary effusion lymphoma, Burkittlymphoma/leukemia, B-cell proliferations of uncertain malignantpotential, lymphomatoid granulomatosis, and post-transplantlymphoproliferative disorder.

Disorders characterized by autoantibody production are often consideredautoimmune diseases. Autoimmune diseases include, but are not limitedto: arthritis, rheumatoid arthritis, juvenile rheumatoid arthritis,osteoarthritis, polychondritis, psoriatic arthritis, psoriasis,dermatitis, polymyositis/dermatomyositis, inclusion body myositis,inflammatory myositis, toxic epidermal necrolysis, systemic sclerodermaand sclerosis, CREST syndrome, responses associated with inflammatorybowel disease, Crohn's disease, ulcerative colitis, respiratory distresssyndrome, adult respiratory distress syndrome (ARDS), meningitis,encephalitis, uveitis, colitis, glomerulonephritis, allergic conditions,eczema, asthma, conditions involving infiltration of T cells and chronicinflammatory responses, atherosclerosis, autoimmune myocarditis,leukocyte adhesion deficiency, systemic lupus erythematosus (SLE),subacute cutaneous lupus erythematosus, discoid lupus, lupus myelitis,lupus cerebritis, juvenile onset diabetes, multiple sclerosis, allergicencephalomyelitis, neuromyelitis optica, rheumatic fever, Sydenham'schorea, immune responses associated with acute and delayedhypersensitivity mediated by cytokines and T-lymphocytes, tuberculosis,sarcoidosis, granulomatosis including Wegener's granulomatosis andChurg-Strauss disease, agranulocytosis, vasculitis (includinghypersensitivity vasculitis/angiitis, ANCA and rheumatoid vasculitis),aplastic anemia, Diamond Blackfan anemia, immune hemolytic anemiaincluding autoimmune hemolytic anemia (AIHA), pernicious anemia, purered cell aplasia (PRCA), Factor VIII deficiency, hemophilia A,autoimmune neutropenia, pancytopertia, leukopenia, diseases involvingleukocyte diapedesis, central nervous system (CNS) inflammatorydisorders, multiple organ injury syndrome, myasthenia gravis,antigen-antibody complex mediated diseases, anti-glomerular basementmembrane disease, anti-phospholipid antibody syndrome, allergicneuritis, Behcet disease, Castleman's syndrome, Goodpasture's syndrome,Lambert-Eaton Myasthenic Syndrome, Reynaud's syndrome, Sjorgen'ssyndrome, Stevens-Johnson syndrome, solid organ transplant rejection,graft versus host disease (GVHD), pemphigoid bullous, pemphigus,autoimmune polyendocrinopathies, seronegative spondyloarthropathies,Reiter's disease, stiff-man syndrome, giant cell arteritis, immunecomplex nephritis, IgA nephropathy, IgM polyneuropathies or IgM mediatedneuropathy, idiopathic thrombocytopenic purpura (ITP), thromboticthrombocytopenic purpura (TTP), Henoch-Schonlein purpura, autoimmunethrombocytopenia, autoimmune disease of the testis and ovary includingautoimmune orchitis and oophoritis, primary hypothyroidism; autoimmuneendocrine diseases including autoimmune thyroiditis, chronic thyroiditis(Hashimoto's Thyroiditis), subacute thyroiditis, idiopathichypothyroidism, Addison's disease, Grave's disease, autoimmunepolyglandular syndromes (or polyglandular endocrinopathy syndromes),Type I diabetes also referred to as insulin-dependent diabetes mellitus(IDDM) and Sheehan's syndrome; autoimmune hepatitis, lymphoidinterstitial pneumonitis (HIV), bronchiolitis obliterans(non-transplant) vs NSIP, Guillain-Barre' Syndrome, large vesselvasculitis (including polymyalgia rheumatica and giant cell (Takayasu's)arteritis), medium vessel vasculitis (including Kawasaki's disease andpolyarteritis nodosa), polyarteritis nodosa (PAN) ankylosingspondylitis, Berger's disease (IgA nephropathy), rapidly progressiveglomerulonephritis, primary biliary cirrhosis, Celiac sprue (glutenenteropathy), cryoglobulinemia, cryoglobulinemia associated withhepatitis, amyotrophic lateral sclerosis (ALS), coronary artery disease,familial Mediterranean fever, microscopic polyangiitis, Cogan'ssyndrome, Whiskott-Aldrich syndrome and thromboangiitis obliterans.

Rheumatoid arthritis (RA) is a chronic disease characterized byinflammation of the joints, leading to swelling, pain, and loss offunction. Patients having RA for an extended period usually exhibitprogressive joint destruction, deformity, disability and even prematuredeath.

Crohn's disease and a related disease, ulcerative colitis, are the twomain disease categories that belong to a group of illnesses calledinflammatory bowel disease (IBD). Crohn's disease is a chronic disorderthat causes inflammation of the digestive or gastrointestinal (GI)tract. Although it can involve any area of the GI tract from the mouthto the anus, it most commonly affects the small intestine and/or colon.In ulcerative colitis, the GI involvement is limited to the colon.

Crohn's disease may be characterized by antibodies against neutrophilantigens, i.e., the “perinuclear anti-neutrophil antibody” (pANCA), andSaccharomyces cervisiae, i.e. the “anti-Saccharomyces cervisiaeantibody” (ASCA). Many patients with ulcerative colitis have the pANCAantibody in their blood, but not the ASCA antibody, while many Crohn'spatients exhibit ASCA antibodies, and not pANCA antibodies. One methodof evaluating Crohn's disease is using the Crohn's disease ActivityIndex (CDAI), based on 18 predictor variables scores collected byphysicians. CDAI values of 150 and below are associated with quiescentdisease; values above that indicate active disease, and values above 450are seen with extremely severe disease [Best et al., “Development of aCrohn's disease activity index.” Gastroenterology 70:439-444 (1976)].However, since the original study, some researchers use a ‘subjectivevalue’ of 200 to 250 as an healthy score.

Systemic Lupus Erythematosus (SLE) is an autoimmune disease caused byrecurrent injuries to blood vessels in multiple organs, including thekidney, skin, and joints. In patients with SLE, a faulty interactionbetween T cells and B-cells results in the production of autoantibodiesthat attack the cell nucleus. There is general agreement thatautoantibodies are responsible for SLE, so new therapies that depletethe B-cell lineage, allowing the immune system to reset as new B-cellsare generated from precursors, would offer hope for long lasting benefitin SLE patients.

Multiple sclerosis (MS) is also an autoimmune disease. It ischaracterized by inflammation of the central nervous system anddestruction of myelin, which insulates nerve cell fibers in the brain,spinal cord, and body. Although the cause of MS is unknown, it is widelybelieved that autoimmune T cells are primary contributors to thepathogenesis of the disease. However, high levels of antibodies arepresent in the cerebral spinal fluid of patients with MS, and sometheories predict that the B-cell response leading to antibody productionis important for mediating the disease.

Autoimmune thyroid disease results from the production of autoantibodiesthat either stimulate the thyroid to cause hyperthyroidism (Graves'disease) or destroy the thyroid to cause hypothyroidism (Hashimoto'sthyroiditis). Stimulation of the thyroid is caused by autoantibodiesthat bind and activate the thyroid stimulating hormone (TSH) receptor.Destruction of the thyroid is caused by autoantibodies that react withother thyroid antigens.

Sjogren's syndrome is an autoimmune disease characterized by destructionof the body's moisture-producing glands.

Immune thrombocytopenic purpura (ITP) is caused by autoantibodies thatbind to blood platelets and cause their destruction.

Myasthenia Gravis (MG) is a chronic autoimmune neuromuscular disordercharacterized by autoantibodies that bind to acetylcholine receptorsexpressed at neuromuscular junctions leading to weakness of thevoluntary muscle groups.

Psoriasis, is characterized by autoimmune inflammation in the skin andalso associated with arthritis in 30% of cases, scleroderma,inflammatory bowel disease, including Crohn's disease and ulcerativecolitis,

Also contemplated is the treatment of idiopathic inflammatory myopathy(IIM), including dermatomyositis (DM) and polymyositis (PM).Inflammatory myopathies have been categorized using a number ofclassification schemes. Miller's classification schema (Miller, RheumDis Din North Am. 20:811-826, 1994) identifies 2 idiopathic inflammatorymyopathies (IIM), polymyositis (PM) and dermatomyositis (DM).

Polymyositis and dermatomyositis are chronic, debilitating inflammatorydiseases that involve muscle and, in the case of DM, skin. Thesedisorders are rare, with a reported annual incidence of approximately 5to 10 cases per million adults and 0.6 to 3.2 cases per million childrenper year in the United States (Targoff, Curr Probl Dermatol. 1991,3:131-180). Idiopathic inflammatory myopathy is associated withsignificant morbidity and mortality, with up to half of affected adultsnoted to have suffered significant impairment (Gottdiener et al., Am JCardiol. 1978, 41:1141-49). Miller (Rheum Dis Clin North Am. 1994,20:811-826 and Arthritis and Allied Conditions, Ch. 75, Eds. Koopman andMoreland, Lippincott Williams and Wilkins, 2005) sets out five groups ofcriteria used to diagnose IIM, i.e., Idiopathic Inflammatory MyopathyCriteria (IIMC) assessment, including muscle weakness, muscle biopsyevidence of degeneration, elevation of serum levels of muscle-associatedenzymes, electromagnetic triad of myopathy, evidence of rashes indermatomyositis, and also includes evidence of autoantibodies as asecondary criteria.

IIM associated factors, including muscle-associated enzymes andautoantibodies include, but are not limited to, creatine kinase (CK),lactate dehydrogenase, aldolase, C-reactive protein, aspartateaminotransferase (AST), alanine aminotransferase (ALT), and antinuclearautoantibody (ANA), myositis-specific antibodies (MSA), and antibody toextractable nuclear antigens.

A “binding molecule” according to the invention can be, for example, aprotein (a “protein” may be polypeptide or peptide), nucleic acid,carbohydrate, lipid, or small molecule compound that binds to a target.A type of proteinaceous binding molecule contemplated by the inventionis an antibody or an antibody fragment that retains binding activity. Abinding molecule may be modified according to methods standard in theart to improve its binding affinity, diminish its immunogenicity, alterits effector functions and/or improve its availability in the body of anindividual. Such modifications may include, for example, amino acidsequence modifications or expression as a fusion protein. Such fusionproteins are also binding molecules according to the invention. Anexemplary binding molecule of the invention is a small modularimmunopharmaceutical (SMIP™).

A binding molecule that is “specific” for a target binds to that targetwith a greater affinity than any other target. For example, aCD37-specific binding molecule binds to CD37 with a greater affinitythan to any other target and a CD20-specific binding molecule binds toCD20 with a greater affinity than to any other target. Binding moleculesof the invention may have affinities for their targets of a Ka ofgreater than or equal to about 10⁴ M⁻¹, preferably of greater than orequal to about 10⁵ M⁻¹, more preferably of greater than or equal toabout 10⁶ M⁻¹ and still more preferably of greater than or equal toabout 10⁷ M⁻¹. Affinities of even greater than about 10⁷ M⁻¹ are stillmore preferred, such as affinities equal to or greater than about 10⁷M¹, about 10⁸ M⁻¹, and about 10⁹ M⁻¹, and about 10¹⁰ M⁻¹. Affinities ofbinding molecules according to the present invention can be readilydetermined using conventional techniques, for example those described byScatchard et al., Ann. N.Y. Acad. Sci. 51:660 (1949).

Certain CD37-specific binding molecules contemplated by the inventionhave affinities for CD37 of about 0.5 to about 100 nM. CertainCD20-specific binding molecules contemplated by the invention haveaffinities for CD20 of about 1 to about 30 nM.

Another characteristic of certain CD37-binding molecules andCD20-binding molecules contemplated by the invention is they exhibit ahalf life in circulation of about 7 to about 30 days.

CD37-specific antibodies that characterized the CD37 antigen in theThird HLDA Workshop were HD28, G28-1, HH1, B114, WR17 and F93G6. See,Ling and MacLennan, pp. 302-335 in Leucocyte Typing Ill. White CellDifferentiation Antigens, Oxford University Press (1987). OtherCD37-specific antibodies that have been described include RFB-7, Y29/55,MB-1, M-B371, M-B372 and IPO-24. See, Moldenhaurer, J. Biol., Regul.Homeost. Agents, 14: 281-283 (2000) which states that all theseantibodies recognize only one CD37 epitope. Schwartz-Albiez et al., 14:905-914 (1988) indicates that the epitope is situated in thecarbohydrate moiety of CD37. Another CD37-specific antibody is S-B3(Biosys).

Patents and patent publications describing CD20 antibodies include U.S.Pat. Nos. 5,776,456, 5,736,137, 6,399,061, and 5,843,439, as well as USpatent application Nos. US 2002/0197255A1 and US 2003/0021781A1(Anderson et al.); U.S. Pat. No. 6,455,043B1 and WO00/09160(Grillo-Lopez, A.); WO00/27428 (Grillo-Lopez and White); WO00/27433(Grillo-Lopez and Leonard); WO00/44788 (Braslawsky et al.); WO01/10462(Rastetter, W.); WO01/10461 (Rastetter and White); WO01/10460 (White andGrillo-Lopez); US appln No. US2002/0006404 and WO2/04021 (Hanna andHariharan); US appln No. US2002/0012665 A1 and WO01/74388 (Hanna, N.);US appln No. US2002/0009444A1, and WO01/80884 (Grillo-Lopez, A.);WO01/97858 (White, C.); US appln No. US2002/0128488A1 and WO02/34790(Reff, M.); WO02/060955 (Braslawsky et al.); WO02/096948 (Braslawsky etal.); WO02/079255 (Reff and Davies); U.S. Pat. No. 6,171,586B1, andWO98/56418 (Lam et al.); WO98/58964 (Raju, S.); WO99/22764 (Raju, S.);WO99/51642, U.S. Pat. No. 6,194,551B1, U.S. Pat. No. 6,242,195B1, U.S.Pat. No. 6,528,624B1 and U.S. Pat. No. 6,538,124 (Idusogie et al.);WO00/42072 (Presta, L.); WO00/67796 (Curd et al.); WO01/03734(Grillo-Lopez et al.); US appln No. US 2002/0004587A1 and WO01/77342(Miller and Presta); US appln No. US2002/0197256 (Grewal, I.); U.S. Pat.Nos. 6,090,365B1, 6,287,537B1, 6,015,542, 5,843,398, and 5,595,721,(Kaminski et al.); U.S. Pat. Nos. 5,500,362, 5,677,180, 5,721,108, and6,120,767 (Robinson et al.); U.S. Pat. No. 6,410,391B1 (Raubitschek etal.); U.S. Pat. No. 6,224,866B1 and WO00/20864 (Barbera-Guillem, E.);WO01/13945 (Barbera-Guillem, E.); WO00/67795 (Goldenberg); WO00/74718(Goldenberg and Hansen); WO00/76542 (Golay et al.); WO01/72333 (Wolinand Rosenblatt); U.S. Pat. No. 6,368,596B1 (Ghetie et al.); US Appln No.US2002/0041847A1, (Goldenberg, D.); US Appln no. US2003/0026801A1(Weiner and Hartmann); WO02/102312 (Engleman, E.), each of which isexpressly incorporated herein by reference. See, also, U.S. Pat. No.5,849,898 and EP appln No. 330,191 (Seed et al.); U.S. Pat. No.4,861,579 and EP332,865A2 (Meyer and Weiss); and WO95/03770 (Bhat etal.).

Rituximab has been approved for human clinical use as Rituxan®. Rituxan®is considered to be a CD20-specific binding molecule of the invention.

Small, modular immunopharmaceuticals (SMIPs) are considered to be onetype of binding molecules of the invention. Methods for making SMIPshave been described previously in co-owned U.S. application Ser. No.10/627,556 and US Patent Publ. 20030133939, 20030118592, and20050136049, which are incorporated herein by reference in theirentirety. SMIPs are novel binding domain-immunoglobulin fusion proteinsthat generally feature a binding domain for a cognate structure such asan antigen, a counterreceptor or the like, an IgG1, IGA or IgE hingeregion polypeptide or a mutant IgG1 hinge region polypeptide havingeither zero, one or two cysteine residues, and immunoglobulin CH2 andCH3 domains. In one embodiment, the binding domain molecule has one ortwo cysteine (Cys) residues in the hinge region. In a relatedembodiment, when the binding domain molecule comprises two Cys residues,the first Cys, which is involved in binding between the heavy chain andlight chain, is not deleted or substituted with an amino acid.

The binding domain of molecules useful in methods of the invention arecontemplated as having one or more binding regions, such as variablelight chain and variable heavy chain binding regions derived from one ormore immunoglobulin superfamily members, such as an immunoglobulin.These regions, moreover, are typically separated by linker peptides,which may be any linker peptide known in the art to be compatible withdomain or region joinder in a binding molecule. Exemplary linkers arelinkers based on the Gly₄Ser linker motif, such as (Gly₄Ser)_(n), wheren=1-5. The molecules for use in the methods of the invention alsocontain sufficient amino acid sequence derived from a constant region ofan immunoglobulin to provide an effector function, preferably ADCCand/or CDC. Thus, the molecules will have a sequence derived from a CH2domain of an immunoglobulin or CH2 and CH3 domains derived from one ormore immunoglobulins. SMIPs are capable of ADCC and/or CDC but arecompromised in their ability to form disulfide-linked multimers.

The invention includes humanized CD37-specific SMIP polypeptides thatexhibit at least 80 percent identity to the polypeptide set forth in SEQID NO: 2, wherein the humanized CD37-specific SMIP polypeptide bindsCD37. In one aspect, the humanized CD37-specific SMIP polypeptidescomprise any amino acid sequence selected from the group consisting ofSEQ ID NOS: 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34,36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 80, 82, 84, 86, and88. In another aspect, the humanized CD37-specific SMIP polypeptidescomprise at least one amino acid modification in acomplementarity-determining region (CDR) selected from the groupconsisting of: light chain CDR1, heavy chain CDR1, light chain CDR2,heavy chain CDR2, light chain CDR3, and heavy chain CDR3.

In one embodiment, the invention includes a humanized CD37-specific SMIPpolypeptide, wherein CDR1 of the light chain comprises the amino acidsequence of SEQ ID NO: 61 (RASENVYSYLA). The invention also includes ahumanized CD37-specific SMIP polypeptide, wherein CDR1 of the lightchain comprises the amino acid sequence of SEQ ID NO: 62 (RTSENVYSYLA).The invention further includes a humanized CD37-specific SMIPpolypeptide, wherein CDR1 of the heavy chain comprises the amino acidsequence of SEQ ID NO: 63 (GYMNM).

In another embodiment, the invention includes a humanized CD37-specificSMIP polypeptide, wherein CDR2 of the light chain comprises the aminoacid sequence of SEQ ID NO: 64 (FAKTLAE). The invention also includes ahumanized CD37-specific SMIP polypeptide, wherein CDR2 of the heavychain comprises the amino acid sequence of SEQ ID NO: 65(NIDPYYGGTTTYNRKFKG).

In a further embodiment, the invention includes a humanizedCD37-specific SMIP polypeptide, wherein CDR3 of the light chaincomprises the amino acid sequence of SEQ ID NO: 66 (QHHSDNPWT). Theinvention further includes a humanized CD37-specific SMIP polypeptide,wherein CDR3 of the heavy chain comprises the amino acid sequence of SEQID NO: 67 (SVGPFDY). The invention further includes a humanizedCD37-specific SMIP polypeptide, wherein CDR3 of the heavy chaincomprises the amino acid sequence of SEQ ID NO: 68 (SVGPFDS). Theinvention also includes a humanized CD37-specific SMIP polypeptide,wherein CDR3 of the heavy chain comprises the amino acid sequence of SEQID NO: 69 (SVGPMDY).

In another aspect, the invention includes a humanized CD37-specific SMIPpolypeptide comprising at least one, at least two, or at least threesequence(s) of the light chain CDR amino acid sequences selected fromthe group consisting of SEQ ID NOS: 61, 62, 64, and 66. In yet anotherembodiment, the invention includes a humanized CD37-specific SMIPpolypeptide comprising a light chain CDR1 amino acid sequence of SEQ IDNOS: 61 or 62, or a variant thereof in which one or two amino acids ofSEQ ID NOS: 61 or 62 has been changed; a light chain CDR2 amino acidsequence of SEQ ID NO: 64, or a variant thereof in which one or twoamino acids of SEQ ID NO: 64 has been changed; and a light chain CDR3amino acid sequence of SEQ ID NO: 66, or a variant thereof in which oneor two amino acids of SEQ ID NO: 66 has been changed.

In still another aspect, the invention includes a humanizedCD37-specific SMIP polypeptide comprising at least one, at least two, orat least three of the heavy chain CDR amino acid sequences selected fromthe group consisting of SEQ ID NOS: 63, 65, and 67-69. In a furtherembodiment, the invention includes a humanized CD37-specific SMIPpolypeptide comprising a heavy chain CDR1 amino acid sequence of SEQ IDNO: 63, or a variant thereof in which one or two amino acids of SEQ IDNO: 63 has been changed; a heavy chain CDR2 amino acid sequence of SEQID NO: 65, or a variant thereof in which one or two amino acids of SEQID NO: 65 has been changed; and a heavy chain CDR3 amino acid sequenceselected from the group consisting of SEQ ID NOS: 67-69, or a variantthereof in which one or two amino acids of any one of SEQ ID NOS: 67-69has been changed.

The invention also includes humanized CD37-specific SMIP polypeptidescomprising at least one amino acid modification in a framework region(FR) selected from the group consisting of: light chain FR1, heavy chainFR1, light chain FR2, heavy chain FR2, light chain FR3, heavy chain FR3,light chain FR4, and heavy chain FR4. In one embodiment, the inventionincludes a humanized CD37-specific SMIP polypeptide, wherein the firstframework region (FR1) of the light chain comprises the amino acidsequence of SEQ ID NO: 70 (EIVLTQSPATLSLSPGERATLSC). In anotherembodiment, the invention includes a humanized CD37-specific SMIPpolypeptide, wherein FR1 of the heavy chain comprises the amino acidsequence of SEQ ID NO: 71 (EVQLVQSGAEVKKPGESLKISCKGSGYSFT). In stillanother embodiment, the invention includes a humanized CD37-specificSMIP polypeptide, wherein FR2 of the light chain comprises the aminoacid sequence of SEQ ID NO: 72 (WYQQKPGQAPRLLIY). In a furtherembodiment, the invention includes a humanized CD37-specific SMIPpolypeptide, wherein FR2 of the heavy chain comprises the amino acidsequence of SEQ ID NO: 73 (WVRQMPGKGLEWMG). In yet another embodiment,the invention includes a humanized CD37-specific SMIP polypeptide,wherein FR3 of the light chain comprises the amino acid sequence of SEQID NO: 74 (GIPARFSGSGSGTDFTLTISSLEPEDFAVYYC). In yet another embodiment,the invention includes a humanized CD37-specific SMIP polypeptide,wherein FR3 of the heavy chain comprises the amino acid sequence of SEQID NO: 75 (QVTISADKSISTAYLQWSSLKASDTAMYYCAR). In yet another embodiment,the invention includes a humanized CD37-specific SMIP polypeptide,wherein FR4 of the light chain comprises the amino acid sequence of SEQID NO: 76 (FGQGTKVEIK). In yet another embodiment, the inventionincludes a humanized CD37-specific SMIP polypeptide, wherein FR4 of theheavy chain comprises the amino acid sequence of SEQ ID NO: 77(WGQGTLVTVSS). In yet another embodiment, the invention includes ahumanized CD37-specific SMIP polypeptide, wherein FR4 of the heavy chaincomprises the amino acid sequence of SEQ ID NO: 78 (WGRGTLVTVSS).

The invention further includes humanized CD37-specific SMIP polypeptidescomprising at least one, at least two, or at least three sequence(s) ofthe light chain FR amino acid sequences selected from the groupconsisting of SEQ ID NOS: 70, 72, 74, and 76. In one embodiment, theinvention includes a humanized CD37-specific SMIP polypeptide comprisinga light chain FR1 amino acid sequence of SEQ ID NO: 70, or a variantthereof in which one or two amino acids of SEQ ID NO: 70 has beenchanged; a light chain FR2 amino acid sequence of SEQ ID NO: 72, or avariant thereof in which one or two amino acids of SEQ ID NO: 72 hasbeen changed; a light chain FR3 amino acid sequence of SEQ ID NO: 74, ora variant thereof in which one or two amino acids of SEQ ID NO: 74 hasbeen changed; and a light chain FR4 amino acid sequence of SEQ ID NO:76, or a variant thereof in which one or two amino acids of SEQ ID NO:76 has been changed.

In addition, the invention includes humanized CD37-specific SMIPpolypeptides comprising at least one, at least two, or at least threesequence(s) of the heavy chain FR amino acid sequences selected from thegroup consisting of SEQ ID NOS: 71, 73, 75, 77, and 78. In oneembodiment, the invention includes a humanized CD37-specific SMIPpolypeptide comprising a heavy chain FR1 amino acid sequence of SEQ IDNO: 71, or a variant thereof in which one or two amino acids of SEQ IDNO: 71 has been changed; a heavy chain FR2 amino acid sequence of SEQ IDNO: 73, or a variant thereof in which one or two amino acids of SEQ IDND: 73 has been changed; a heavy chain FR3 amino acid sequence of SEQ IDND: 75, or a variant thereof in which one or two amino acids of SEQ IDNO: 75 has been changed; and a heavy chain FR4 amino acid sequence ofSEQ ID NOS: 77 or 78, or a variant thereof in which one or two aminoacids of SEQ ID NOS: 77 or 78 has been changed.

The invention also includes an isolated nucleic acid molecule comprisinga nucleotide sequence encoding a humanized CD37-specific SMIPpolypeptide that exhibits at least 80 percent identity to thepolypeptide set forth in SEQ ID NO: 2, wherein the humanizedCD37-specific SMIP polypeptide binds CD37. Such an isolated nucleic acidmolecule may comprise a nucleotide sequence selected from the groupconsisting of: SEQ ID NOS: 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27,29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 79, 81,83, 85, and 87. In one embodiment, the invention includes vectors thatcomprise these nucleic acid molecules and host cells that comprise thevectors.

The invention also includes processes of producing the polypeptidesdescribed herein, comprising culturing the host cells under suitableconditions to express the polypeptides, and optionally isolating thepolypeptides from the culture.

In yet another aspect, the invention includes compositions comprisingthe humanized CD37-specific SMIP polypeptides of the invention and apharmaceutically acceptable carrier.

The invention further includes using the CD37-specific SMIP orCD37-specific binding molecules described herein in any of the methodsof the invention. Such methods include the use of any of theCD37-specific SMIP or CD37-specific binding molecule comprising an aminoacid sequence selected from the group consisting of SEQ ID NOS: 6, 8,10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44,46, 48, 50, 52, 54, 56, 58, 60, 80, 82, 84, 86, and 88.

In yet another aspect, the invention includes kits for reducing B-cellscomprising the compositions of the invention; and protocols for usingthe kits to reduce B cells. Such kits may further comprise one or moreCD20-specific binding molecule(s). The invention contemplates that sucha CD20-specific binding molecule is TRU-015.

The invention also includes humanized CD37-specific SMIP polypeptidescomprising a CDR1, a CDR2, and a CDR3, that exhibits at least 80 percentidentity to the polypeptide set forth in SEQ ID NO: 2. SuchCD37-specific SMIP polypeptides may further comprise a human frameworkdomain separating each of CDR1, CDR2, and CDR3.

In another aspect, the invention includes a humanized CD37-specific SMIPpolypeptide that exhibits at least 80 percent identity to thepolypeptide set forth in SEQ ID NO: 2, wherein the humanizedCD37-specific SMIP polypeptide binds CD37 and comprises a hinge regionpolypeptide comprising an amino acid sequence selected from the groupconsisting of SEQ ID NOS: 90, 92, 94, 96, 98, 100, 102, 104, 106, 108110, 112, 114, 115, 116, 118, 120, 122, 124, 126 and 127.

The invention also contemplates a humanized CD37-specific SMIPpolypeptide that exhibits at least 80 percent identity to thepolypeptide set forth in SEQ ID NO: 2, wherein the humanizedCD37-specific SMIP polypeptide binds CD37 and comprises a linkercomprising (Gly₄Ser)_(n), wherein n is 1, 2, 3, 4, 5, or 6.

In still a further aspect, the invention includes a humanizedCD37-specific SMIP polypeptide, wherein CDR1 of the light chaincomprises the amino acid sequence selected from the group consisting ofSEQ ID NOS: 128 (RTSQNVYSYLA), 129 (RTSESVYSYLA), 130 (RASQSVYSYLA), 131(RASQSVSSYLA) and 132 (RASQSVSYYLA). In another embodiment, theinvention includes a humanized CD37-specific SMIP polypeptide, whereinCDR1 of the heavy chain comprises the amino acid sequence selected fromthe group consisting of SEQ ID NOS: 133 (SYMNM) and 134 (SYWIG). In afurther embodiment, the invention includes a humanized CD37-specificSMIP polypeptide, wherein CDR2 of the light chain comprises the aminoacid sequence selected from the group consisting of SEQ ID NOS: 135(AASSLQS), 136 (GASTRAT) and 137 (DASNRAT). In still another embodiment,the invention includes a humanized CD37-specific SMIP polypeptide,wherein CDR2 of the heavy chain comprises the amino acid sequenceselected from the group consisting of SEQ ID NOS: 138(IIYPGDSDTRYSPSFQG) and 139 (RIDPSDSYTNYSPSFQG).

The invention also includes a humanized CD37-specific SNP polypeptide,wherein CDR3 of the light chain comprises the amino acid sequence of SEQID NO: 220 (QHHSDNPWT). In another embodiment, the invention includes ahumanized CD37-specific SMIP polypeptide, wherein CDR3 of the heavychain comprises the amino acid sequence selected from the groupconsisting of SEQ ID NOS: 211 (SVGPMDY), 212 (SVGPFDY), 213 (SVGPMDV),214 (SVGPFDS), 215 (SVGPFDP), 216 (SVGPFQH), 217 (SVGPFDV), 218(SVGPFD1) and 219 (SVGPFDL).

In still a further aspect, the invention includes CD37-specific SMIPpolypeptides with alternative framework regions. in one aspect, theinvention includes a humanized CD37-specific SMIP polypeptide, whereinFR1 of the light chain comprises the amino acid sequence selected fromthe group consisting of SEQ ID NOS: 170-181. In another aspect, theinvention includes a humanized CD37-specific SMIP polypeptide, whereinFR1 of the heavy chain comprises the amino acid sequence selected fromthe group consisting of SEQ ID NOS: 140-146. In a still further aspect,the invention includes a humanized CD37-specific SMIP polypeptide,wherein FR2 of the light chain comprises the amino acid sequenceselected from the group consisting of SEQ ID NOS: 182-193. In yetanother aspect, the invention includes a humanized CD37-specific SMIPpolypeptide, wherein FR2 of the heavy chain comprises the amino acidsequence selected from the group consisting of SEQ ID NOS: 147-153. Inan additional aspect, the invention includes a humanized CD37-specificSMIP polypeptide, wherein FR3 of the light chain comprises the aminoacid sequence selected from the group consisting of SEQ ID NOS: 194-205.In yet another aspect, the invention includes a humanized CD37-specificSMIP polypeptide, wherein FR3 of the heavy chain comprises the aminoacid sequence selected from the group consisting of SEQ ID NOS: 154-160.In a further aspect, the invention includes a humanized CD37-specificSMIP polypeptide, wherein FR4 of the light chain comprises the aminoacid sequence selected from the group consisting of SEQ ID NOS: 206-210.In yet another aspect, the invention includes a humanized CD37-specificSMIP polypeptide, wherein FR4 of the heavy chain comprises the aminoacid sequence selected from the group consisting of SEQ ID NOS: 161-169.

Exemplary CD37-specific SMIPs useful in the invention include, but arenot limited to: G28-1 scFv (SSS-S) H WCH2 WCH3, consists of a G28-1single chain Fv in which all three cysteine residues in the connectionor hinge regions are mutated to serine residues, and wild type CH2 andCH3 domains; G28-1 scFv IgAH WCH2 WCH3, comprising an IgA hinge and WTIgG1 domains; 028-1 scFv VHL11S (SSS-S) H WCH2 CH3 in which all threecysteine residues in the connection or hinge regions are mutated toserine residues and the leucine at position 11 of the heavy chainvariable region is substituted with a serine; G28-1 scFv VH L11 S(CSS-S)H WCH2 CH3, in which cysteine residues were substituted at the secondand third positions with serine; G28-1 scFv VHL11S(CSC-S) H WCH2 CH3, inwhich cysteine residues were substituted at the second position withserine; G28-1 scFv VH11S(SSC-P) H WCH2 WCH3 (referred to as TRU-016herein), in which the first and second cysteine residues in theconnection or hinge regions are mutated to serine residues and theleucine at position 11 of the heavy chain variable region is substitutedwith a serine; G28-1 scFv VH11S(SCS-S) H WCH2 WCH3, in which the firstand third cysteine residues in the hinge regions are mutated to serineresidues; 028-1 scFv VHL11S(CCS-P) H WCH2 WCH3, in which the thirdcysteine residue in the hinge region is substituted with a serine;G28-1scFv VHL11S(SCC-P) H WCH2 WCH3, in which the first cysteine issubstituted with a serine; 028-1 scFv VH L11S mIgE CH2 CH3 CH4,comprising mouse IgE CH 2-4 regions in which the leucine at position 11of the heavy chain variable region is substituted with a serine; G28-1scFv VH LI 1S mIgA WIgACH2 T4-CH3, comprising a mouse IgA hinge with awild type IgA CH2 and a truncated IgA CH3 domain lacking the 4 carboxyamino acids GTCY; G28-1 scFv VHL11S hIgE CH2 CH3 CH4, comprising IgE CHregions in which the leucine at position 11 of the heavy chain variableregion is substituted with a serine; and G28-1 scFv VHL11S hIgAH WIgACH2TCH3, comprising an IgA hinge, a wild type IgA CH2 and a truncated IgACH2 and a truncated IgA CH3 domain lacking the 4 carboxy amino acidsGTCY.

Exemplary CD20-specific SMIPs useful in the invention include SMIPsderived from the anti-CD20 monoclonal antibody 2H7 described in USPatent Publ. 2003133939. and 20030118592. The SMIPs include 2H7scFv-Igor a derivative thereof. Derivatives includes CytoxB-MHWTG1C, which hasa human IgG1 Fc domain and a mutant IgG1 hinge domain; CytoxB-MHMG1C,which comprises a mutated Fc domain; MG1H/MG1C, which comprises an Fcreceptor with a mutated leucine residue 234; CytoxB-IgAHWTHG1C,comprising a portion of the human IgA hinge fused to wild-type human Fcdomain; 2H7 scFv-llama IgG1, comprising the llama IgG1 hinge and CH2CH3regions, 2H7 scFv-Ilama IgG2, comprising the llama IgG2 hinge and CH2CH3regions; 2H7 scFv-llama IgG3, comprising the llama IgG3 hinge and CH2CH3regions.

H7 scFv MTH (SSS) WTCH2CH3, in which all three cysteine residues in theconnection or hinge regions are mutated to serine residues, and wildtype CH2 and CH3 domains; 2H7 scFv MTH (SSC), in which the first twocysteine residues were substituted with serine residues; 2H7 scFv MTH(SCS), in which the first and third cysteines were substituted withserine residues; 2H7 scFv MTH (CSS) WTCH2CH3, in which cysteine residueswere substituted at the second and third positions with serine; 2H7 scFvVH11SER IgG MTH (SSS) WTCH2CH3, in which the leucine at position 11 inthe heavy chain variable region is substituted with serine; 2H7 scFv IgAhinge-IgG1 CH2-CH3, comprising an IgA hinge region and WT IgG1 domains;2H7 scFv IgA hinge-CH2-CH3, comprising IgA hinge, CH2-3 regions; 2H7IgAWH IgACH2-T4-CH3, comprising an IgA hinge, a wild type IgA CH2 and atruncated IgA CH3 domain lacking the 4 carboxy amino acids GTCY.

Derivatives with mutations in the IgG CH3 region include 2H7 scFv MTHWTCH2 MTCH3 Y405, in which phenylalanine residue at position 405(numbering according to Kabat et al. supra) was substituted withtyrosine; 2H7 scFv MTH WTCH2 MTCH3 A405, in which phenylalanine positionat 405 was substituted with an alanine; scFv MTH WTCH2 MTCH3 A407, inwhich tyrosine residue at position 407 was substituted with an alanine;scFv MTH WTCH2 MTCH3 Y405A407, comprising the two mutations; and scFvMTH WTCH2 MTCH3 A405A407 comprising two mutations.

2H7 scFv MTH (CCS) WTCH2CH3 is a construct with the third cysteineresidue in the IgG1 hinge region substituted with a serine residue. The2H7 scFv IgG MTH (555) MTCH2WTCH3 SMIP comprises mutant hinge (MT (55S))and a mutant CH2 domain in which the proline at residue 238 (accordingto Ward et al.,) was substituted with a serine.

H7scFv-Ig derivatives also include 2H7 scFv mutants with point mutationsin the variable heavy chain region. The following constructs allcomprise mutations in which the leucine at position 11 in the heavychain variable region is substituted with serine: 2H7 scFv VH11SER IgGMTH (SSS-S) WTCH2CH3, 2H7scFv VHL11S(CSS-S) H WCH2 WCH3, comprising amutated hinge region as set out above; 2H7scFv VHL115 (CSC-5) H WCH2WCH3 comprising a mutated hinge region as set out above; 2H7 scFv VHL115IgAH IgACH2 T4CH3, comprises the IgA hinge, WT IgA CH2 and truncated IgACH3; 2H7 scFv VHL11S IgECH2 CH3 CH4, comprising the IgE CH 2-4 regions;2H7 VHL115 scFv (SSS-S) IgECH3CH4, comprising a mutated hinge region andIgE CH3 and CH4 regions; 2H7 scFv VH L11S mIgE CH2 CH3 CH4, comprisesmouse IgE regions; 2H7 scFv VH L11S mIgAH WIGACH2 T4CH3 comprises themutations described above and a mouse IgA constant region consisting ofa wild type CH2 region and a mutated CH3 region; 2H7 scFv VH L115(55S-5) H K3225 CH2 WCH3 comprises a mutation in the human IgG1 CH2region at residue 322, where lysine was changed to serine; 2H7 scFv VHL11S(CSS-S) H K3225 CH2 WCH3 comprises a mutated hinge region asdescribed above, and a mutated CH2 region as previously described; 2H7scFv VH L11S(SSS-S) H P331S CH2 WCH3, comprises a mutated hinge regionas described above, and a mutated CH2 region in which praline at residue331 was changed to a serine; 2H7 scFv VH L11S(CSS-S) H P331S CH2 WCH3comprises a mutated hinge region and a praline to serine mutation atresidue 331 in the CH2 region; 2H7 scFv VH L11S(SSS-S) H T256N CH2 WCH3,comprises a mutated hinge region and a threonine to asparagine mutationat residue 256 in the CH2 region; 2H7 scFv VH L11S(SSS-S) H RTPE/QNAK(255-258) CH2 WCH3, comprises a mutated hinge region and a series ofmutations in which residues 255-258 have been mutated from arginine,threonine, praline, glutamic acid to glutamine, asparagines, alanine andlysine, respectively; 2H7 scFv VH L11S(SSS-S) H K290Q CH2 WCH3,comprises a mutated hinge regions and a lysine to glutamine change atposition 290; 2H7 scFv VH L11S(SSS-S) H A339P CH2 WCH3, comprises amutated hinge region and an alanine to praline change at position 339;SMIP 2H7 scFv (SSS-S) H P238SCH2 WCH3, comprises a mutated hinge regionand an proline to serine change at position 238 in CH2, which is thesame as 2H7 scFv IgG MTH (SSS) MTCH2WTCH3. 2H7 scFv IgAH IGAHCH2 TI8CH3comprises a wild type IgA hinge and CH2 region and a CH3 region with an18 amino acid truncation at the carboxy end.

A binding molecule of the invention may comprise a native or engineeredextracellular domain from another protein which improves the bindingmolecule activity. In one embodiment, the extracellular domain isselected from the group consisting of CD154 and CTLA4.

A “synergistic combination” of CD37-specific binding molecules andCD20-specific binding molecules is a combination that has an effect thatis greater than the sum of the effects of the binding molecules whenadministered alone.

In one aspect of the invention, the binding molecules are administeredin one or more pharmaceutical compositions. To administer the bindingmolecules to human or test animals, it is preferable to formulate thebinding molecules in a composition comprising one or morepharmaceutically acceptable carriers. The phrase “pharmaceutically orpharmacologically acceptable” refer to molecular entities andcompositions that do not produce allergic, or other adverse reactionswhen administered using routes well-known in the art, as describedbelow. “Pharmaceutically acceptable carriers” include any and allclinically useful solvents, dispersion media, coatings, antibacterialand antifungal agents, isotonic and absorption delaying agents and thelike.

In addition, compounds may form solvates with water or common organicsolvents. Such solvates are contemplated as well.

The binding molecule compositions may be administered orally, topically,transdermally, parenterally, by inhalation spray, vaginally, rectally,or by intracranial injection. The term parenteral as used hereinincludes subcutaneous injections, intravenous, intramuscular,intracisternal injection, or infusion techniques. Administration byintravenous, intradermal, intramuscular, intramammary, intraperitoneal,intrathecal, retrobulbar, intrapulmonary injection and or surgicalimplantation at a particular site is contemplated as well. Generally,compositions are essentially free of pyrogens, as well as otherimpurities that could be harmful to the recipient. Injection, especiallyintravenous, is preferred.

Pharmaceutical compositions of the present invention containing bindingmolecules used in a method of the invention may contain pharmaceuticallyacceptable carriers or additives depending on the route ofadministration. Examples of such carriers or additives include water, apharmaceutical acceptable organic solvent, collagen, polyvinyl alcohol,polyvinylpyrrolidone, a carboxyvinyl polymer, carboxymethylcellulosesodium, polyacrylic sodium, sodium alginate, water-soluble dextran,carboxymethyl starch sodium, pectin, methyl cellulose, ethyl cellulose,xanthan gum, gum Arabic, casein, gelatin, agar, diglycerin, glycerin,propylene glycol, polyethylene glycol, Vaseline, paraffin, stearylalcohol, stearic acid, human serum albumin (HSA), mannitol, sorbitol,lactose, a pharmaceutically acceptable surfactant and the like.Additives used are chosen from, but not limited to, the above orcombinations thereof, as appropriate, depending on the dosage form ofthe present invention.

Formulation of the pharmaceutical composition will vary according to theroute of administration selected (e.g., solution, emulsion). Anappropriate composition comprising the antibody to be administered canbe prepared in a physiologically acceptable vehicle or carrier. Forsolutions or emulsions, suitable carriers include, for example, aqueousor alcoholic/aqueous solutions, emulsions or suspensions, includingsaline and buffered media. Parenteral vehicles can include sodiumchloride solution, Ringer's dextrose, dextrose and sodium chloride,lactated Ringer's or fixed oils. Intravenous vehicles can includevarious additives, preservatives, or fluid, nutrient or electrolytereplenishers.

A variety of aqueous carriers, e.g., water, buffered water, 0.4% saline,0.3% glycine, or aqueous suspensions may contain the active compound inadmixture with excipients suitable for the manufacture of aqueoussuspensions. Such excipients are suspending agents, for example sodiumcarboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose,sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia;dispersing or wetting agents may be a naturally-occurring phosphatide,for example lecithin, or condensation products of an alkylene oxide withfatty acids, for example polyoxyethylene stearate, or condensationproducts of ethylene oxide with long chain aliphatic alcohols, forexample heptadecaethyl-eneoxycetanol, or condensation products ofethylene oxide with partial esters derived from fatty acids and ahexitol such as polyoxyethylene sorbitol monooleate, or condensationproducts of ethylene oxide with partial esters derived from fatty acidsand hexitol anhydrides, for example polyethylene sorbitan monooleate.The aqueous suspensions may also contain one or more preservatives, forexample ethyl, or n-propyl, p-hydroxybenzoate.

The binding molecule compositions can be lyophilized for storage andreconstituted in a suitable carrier prior to use. This technique hasbeen shown to be effective with conventional immunoglobulins. Anysuitable lyophilization and reconstitution techniques can be employed.It will be appreciated by those skilled in the art that lyophilizationand reconstitution can lead to varying degrees of antibody activity lossand that use levels may have to be adjusted to compensate.

Dispersible powders and granules suitable for preparation of an aqueoussuspension by the addition of water provide the active compound inadmixture with a dispersing or wetting agent, suspending agent and oneor more preservatives. Suitable dispersing or wetting agents andsuspending agents are exemplified by those already mentioned above.

The concentration of binding molecule in these formulations can varywidely, for example from less than about 0.5%, usually at or at leastabout 1% to as much as 15 or 20% by weight and will be selectedprimarily based on fluid volumes, viscosities, etc., in accordance withthe particular mode of administration selected. Thus, a typicalpharmaceutical composition for parenteral injection could be made up tocontain 1 mL sterile buffered water, and 50 mg of antibody. A typicalcomposition for intravenous infusion could be made up to contain 250 mLof sterile Ringer's solution, and 150 mg of antibody. Actual methods forpreparing parenterally administrable compositions will be known orapparent to those skilled in the art and are described in more detailin, for example, Remington's Pharmaceutical Science, 15th ed., MackPublishing Company, Easton, Pa. (1980). An effective dosage of antibodyis within the range of 0.01 mg to 1000 mg per kg of body weight peradministration.

The pharmaceutical compositions may be in the form of a sterileinjectable aqueous, oleaginous suspension, dispersions or sterilepowders for the extemporaneous preparation of sterile injectablesolutions or dispersions. The suspension may be formulated according tothe known art using those suitable dispersing or wetting agents andsuspending agents which have been mentioned above. The sterileinjectable preparation may also be a sterile injectable solution orsuspension in a non-toxic parenterally-acceptable diluent or solvent,for example as a solution in 1,3-butane dial. The carrier can be asolvent or dispersion medium containing, for example, water, ethanol,polyol (for example, glycerol, propylene glycol, and liquid polyethyleneglycol, and the like), suitable mixtures thereof, vegetable oils,Ringer's solution and isotonic sodium chloride solution, In addition,sterile, fixed oils are conventionally employed as a solvent orsuspending medium. For this purpose any bland fixed oil may be employedincluding synthetic mono- or diglycerides. In addition, fatty acids suchas oleic acid find use in the preparation of injectables.

In all cases the form must be sterile and must be fluid to the extentthat easy syringability exists. The proper fluidity can be maintained,for example, by the use of a coating, such as lecithin, by themaintenance of the required particle size in the case of dispersion andby the use of surfactants. It must be stable under the conditions ofmanufacture and storage and must be preserved against the contaminatingaction of microorganisms, such as bacteria and fungi. The prevention ofthe action of microorganisms can be brought about by variousantibacterial an antifungal agents, for example, parabens,chlorobutanol, phenol, sorbic acid, thimerosal, and the like. In manycases, it will be desirable to include isotonic agents, for example,

sugars or sodium chloride. Prolonged absorption of the injectablecompositions can be brought about by the use in the compositions ofagents delaying absorption, for example, aluminum monostearate andgelatin.

Compositions useful for administration may be formulated with uptake orabsorption enhancers to increase their efficacy. Such enhancers includefor example, salicylate, glycocholateilinoleate, glycholate, aprotinin,bacitracin, SDS, caprate and the like. See, e.g., Fix (J. Pharm. Sci.,85:1282-1285, 1996) and Oliyai and Stella (Ann. Rev. Pharmacol.Toxicol., 32:521-544, 1993).

In addition, the properties of hydrophilicity and hydrophobicity of thecompositions contemplated for use in the invention are well balanced,thereby enhancing their utility for both in vitro and especially in vivouses, while other compositions lacking such balance are of substantiallyless utility. Specifically, compositions contemplated for use in theinvention have an appropriate degree of solubility in aqueous mediawhich permits absorption and bioavailability in the body, while alsohaving a degree of solubility in lipids which permits the compounds totraverse the cell membrane to a putative site of action. Thus, antibodycompositions contemplated are maximally effective when they can bedelivered to the site of target antigen activity.

In one aspect, methods of the invention include a step of administrationof a binding molecule composition.

Methods of the invention are performed using any medically-acceptedmeans for introducing a therapeutic directly or indirectly into amammalian individual, including but not limited to injections, oralingestion, intranasal, topical, transdermal, parenteral, inhalationspray, vaginal, or rectal administration. The term parenteral as usedherein includes subcutaneous, intravenous, intramuscular, andintracistemal injections, as well as catheter or infusion techniques.Administration by, intradermal, intramammary, intraperitoneal,intrathecal, retrobulbar, intrapulmonary injection and or surgicalimplantation at a particular site is contemplated as well.

In one embodiment, administration is performed at the site of a canceror affected tissue needing treatment by direct injection into the siteor via a sustained delivery or sustained release mechanism, which candeliver the formulation internally. For example, biodegradablemicrospheres or capsules or other biodegradable polymer configurationscapable of sustained delivery of a composition (e.g., a solublepolypeptide, antibody, or small molecule) can be included in theformulations of the invention implanted near the cancer.

Therapeutic compositions may also be delivered to the patient atmultiple sites. The multiple administrations may be renderedsimultaneously or may be administered over a period of time. In certaincases it is beneficial to provide a continuous flow of the therapeuticcomposition. Additional therapy may be administered on a period basis,for example, hourly, daily, weekly or monthly.

Binding molecule compositions of the invention may comprise one, or maycomprise more than one, binding molecules. Also contemplated by thepresent invention is the administration of binding molecule compositionsin conjunction with a second agent, Second agents contemplated by theinvention are listed in paragraphs below.

A second agent may be a B-cell-associated molecule. OtherB-cell-associated molecules contemplated by the invention includebinding molecules which bind to B-cell surface molecules that are notCD37 or CD20. B-cell-associated molecules, include but are not limitedto, CD19 (B-lymphocyte antigen CD19, also referred to as B-lymphocytesurface antigen B4, or Leu-12), CD21, CD22 (B-cell receptor CD22, alsoreferred to as Leu-14, B-lymphocyte cell adhesion molecule, or BL-CAM),CD23, CD40 (B-cell surface antigen CD40, also referred to as TumorNecrosis Factor receptor superfamily member 5, CD40L receptor, or Bp50),CD80 (T lymphocyte activation antigen CD80, also referred to asActivation 37-1 antigen, B7, B7-1, or BB1), CD86 (T lymphocyteactivation antigen CD86, also referred to as Activation B7-2 antigen,B70, FUN-1, or BU63), CD137 (also referred to as Tumor Necrosis Factorreceptor superfamily member 9), CD152 (also referred to as cytotoxicT-lymphocyte protein 4 or CTLA-4), L6 (Tumor-associated antigen L6, alsoreferred to as Transmembrane 4 superfamily member 1, Membrane componentsurface marker 1, or M3S1), CD30 (lymphocyte activation antigen CD30,also referred to as Tumor Necrosis Factor receptor superfamily member 8,CD3OL receptor, or Ki-1), CD50 (also referred to as Intercellularadhesion molecule-3 (ICAM3), or ICAM-R), CD54 (also referred to asIntercellular adhesion molecule-1 (ICAMI), or Major group rhinovirusreceptor), 37-H1 (ligand for an immunoinhibitory receptor expressed byactivated T cells, B-cells, and myeloid cells, also referred to asPD-L1; see Dong, et al., “B7-H1, a third member of the B7 family,co-stimulates T-cell proliferation and interleukin-10 secretion,” Nat.Med., 5:1365-1369 (1999), CD134 (also referred to as Tumor NecrosisFactor receptor superfamily member 4, OX40, OX4OL receptor, ACT35antigen, or TAX-transcriptionally activated glycoprotein 1 receptor),41BB (4-1BB ligand receptor, T-cell antigen 4-1BB, or T-cell antigenILA), CD153 (also referred to as Tumor Necrosis Factor ligandsuperfamily member 8, CD30 ligand, or CD3O-L), CD154 (also referred toas Tumor Necrosis Factor ligand superfamily member 5, TNF-relatedactivation protein, TRAP, or T cell antigen Gp39) and Toll receptors.The above list of construct targets and/or target antigens is exemplaryonly and is not exhaustive.

Cytokines and growth factors are second agents contemplated by theinvention and include, without limitation, one or more of TNF, 1L, IL-2,IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-11, IL-12, IL-13,IL-14, IL-15, IL-16, IL-17, IL-18, IFN, G-CSF, Meg-CSF, GM-CSF,thrombopoietin, stem cell factor, and erythropoietin. Pharmaceuticalcompositions in accordance with the invention may also include otherknown angiopoietins, for example Ang-1, Ang-2, Ang-4, Ang-Y, and/or thehuman angiopoietin-like polypeptide, and/or vascular endothelial growthfactor (VEGF). Growth factors for use in pharmaceutical compositions ofthe invention include angiogenin, bone morphogenic protein-1, bonemorphogenic protein-2, bone morphogenic protein-3, bone morphogenicprotein-4, bone morphogenic protein-5, bone morphogenic protein-6, bonemorphogenic protein-7, bone morphogenic protein-8, bone morphogenicprotein-9, bone morphogenic protein-10, bone morphogenic protein-11,bone morphogenic protein-12, bone morphogenic protein-13, bonemorphogenic protein-14, bone morphogenic protein-15, bone morphogenicprotein receptor IA, bone morphogenic protein receptor IB, brain derivedneurotrophic factor, ciliary neutrophic factor, ciliary neutrophicfactor receptor α, cytokine-induced neutrophil chemotactic factor 1,cytokine-induced neutrophil chemotactic factor 2α, cytokine-inducedneutrophil chemotactic factor 2β, β endothelial cell growth factor,endothelin 1, epidermal growth factor, epithelial-derived neutrophilattractant, fibroblast growth factor 4, fibroblast growth factor 5,fibroblast growth factor 6, fibroblast growth factor 7, fibroblastgrowth factor 8, fibroblast growth factor 8b, fibroblast growth factor8c, fibroblast growth factor 9, fibroblast growth factor 10, fibroblastgrowth factor acidic, fibroblast growth factor basic, glial cellline-derived neutrophic factor receptor α1, glial cell line-derivedneutrophic factor receptor α2, growth related protein, growth relatedprotein a, growth-related protein β, growth related protein γ, heparinbinding epidermal growth factor, hepatocyte growth factor, hepatocytegrowth factor receptor, insulin-like growth factor I, insulin-likegrowth factor receptor, insulin-like growth factor II, insulin-likegrowth factor binding protein, keratinocyte growth factor, leukemiainhibitory factor, leukemia inhibitory factor receptor a, nerve growthfactor, nerve growth factor receptor, neurotrophin-3, neurotrophin-4,placenta growth factor, placenta growth factor 2, platelet derivedendothelial cell growth factor, platelet derived growth factor, plateletderived growth factor A chain, platelet derived growth factor AA,platelet derived growth factor AB, platelet derived growth factor Bchain, platelet derived growth factor BB, platelet derived growth factorreceptor a, platelet derived growth factor receptor β, pre-B cell growthstimulating factor, stem cell factor, stem cell factor receptor,transforming growth factor a, transforming growth factor β, transforminggrowth factor β1, transforming growth factor β1.2, transforming growthfactor β2, transforming growth factor β3, transforming growth factor β5,latent transforming growth factor β1, transforming growth factor βbinding protein I, transforming growth factor β binding protein II,transforming growth factor β binding protein III, tumor necrosis factorreceptor type I, tumor necrosis factor receptor type 11, urokinase-typeplasminogen activator receptor, vascular endothelial growth factor, andchimeric proteins and biologically or immunologically active fragmentsthereof.

Examples of chemotherapeutic agents contemplated as second agentsinclude, but are not limited to, alkylating agents, such as nitrogenmustards (e.g., mechlorethamine, cyclophosphamide, ifosfamide,melphalan, and chlorambucil); nitrosoureas (e.g., carmustine (BCNU),lomustine (CCNU), and semustine (methyl-CCNU)); ethyleneimines andmethyl-melamines (e.g., triethylenemelamine (TEM), triethylenethiophosphoramide (thiotepa), and hexamethylmelamine (HMM,altretamine)); alkyl sulfonates (e.g., buslfan); and triazines (e.g.,dacabazine (DTIC)); antimetabolites, such as folic acid analogs (e.g.,methotrexate, trimetrexate, and pemetrexed (multi-targeted antifolate));pyrimidine analogs (such as 5-fluorouracil (5-FU), fluorodeoxyuridine,gemcitabine, cytosine arabinoside (AraC, cytarabine), 5-azacylidine, and2,2′-difluorodeoxycytidine); and purine analogs (e.g, 6-mercaptopurine,6-thioguanine, azathioprine, 2′-deoxycoformycin (pentostatin),erythrohydroxynonyiadenine (EHNA), fludarabine phosphate,2-chlorodeoxyadenosine (cladribine, 2-CdA)); Type 1 topoisomeraseinhibitors such as camptothecin (CPT), topotecan, and irinotecan;natural products, such as epipodophylotoxins (e.g., etoposide andteniposide); and vinca alkaloids (e.g., vinblastine, vincristine, andvinorelbine); anti-tumor antibiotics such as actinomycin D, doxorubicin,and bieomycin; radiosensitizers such as 5-bromodeozyuridine,5-iododeoxyuridine, and bromodeoxycytidine; platinum coordinationcomplexes such as cisplatin, carboplatin, and oxaliplatin; substitutedureas, such as hydroxyurea; and methylhydrazine derivatives such asN-methylhydrazine (MIH) and procarbazine.

Non-limiting examples of chemotherapeutic agents, radiotherapeuticagents and other active and ancillary agents are also shown in Table 1.

TABLE 1 Alkylating agents Nitrogen mustards MechlorethamineCyclophosphamide ifosfamide melphalan chlorambucil Nitrosoureascarmustine (BCNU) lomustine (CCNU) semustine (methyl-CCNU)Ethylenemine/Methyl-melamine thriethylenemelamine (TEM) triethylenethiophosphoramide (thiotepa) hexamethylmelamine (HMM, altretamine) Alkylsulfonates busulfan Triazines dacarbazine (DTIC) Antimetabolites FolicAcid analogs methotrexate Trimetrexate Pemetrexed (Multi-targetedantifolate) Pyrimidine analogs 5-fluorouracil fluorodeoxyuridinegemcitabine cytosine arabinoside (AraC, cytarabine) 5-azacytidine2,2′-difluorodeoxy-cytidine Purine analogs 6-mercaptopurine6-thioguanine azathioprine 2′-deoxycoformycin (pentostatin)erythrohydroxynonyl-adenine (EHNA) fludarabine phosphate2-chlorodeoxyadenosine (cladribine, 2-CdA) Type I TopoisomeraseInhibitors camptothecin topotecan irinotecan Biological responsemodifiers G-CSF GM-CSF Differentiation Agents retinoic acid derivativesHormones and antagonists Adrenocorticosteroids/antagonists prednisoneand equivalents dexamethasone ainoglutethimide Progestinshydroxyprogesterone caproate medroxyprogesterone acetate megestrolacetate Estrogens diethylstilbestrol ethynyl estradiol/equivalentsAntiestrogen tamoxifen Androgens testosterone propionatefluoxymesterone/equivalents Antiandrogens flutamidegonadotropin-releasing hormone analogs Leuprolide Nonsteroidalantiandrooens flutamide Natural products Antimitotic drugs Taxanespaclitaxel Vinca alkaloids vinblastine (VLB) vincristine vinorelbineTaxotere ® (docetaxel) estramustine estramustine phosphateEpipodophylotoxins etoposide teniposide Antibiotics actimomycin Ddaunomycin (rubido-mycin) doxorubicin (adria-mycin)mitoxantroneidarubicin bleomycin splicamycin (mithramycin) mitomycinCdactinomycin aphidicolin Enzymes L-asparaginase L-arginaseRadiosensitizers metronidazole misonidazole desmethylmisonidazolepimonidazole etanidazole nimorazole RSU 1069 EO9 RB 6145 SR4233nicotinamide 5-bromodeozyuridine 5-iododeoxyuridine bromodeoxycytidineMiscellaneous agents Platinium coordination complexes cisplatinCarboplatin oxaliplatin Anthracenedione mitoxantrone Substituted ureahydroxyurea Methylhydrazine derivatives N-methylhydrazine (MIH)procarbazine Adrenocortical suppressant mitotane (o,p′-DDD)ainoglutethimide Cytokines interferon (a, β, γ) interleukin-2Photosensitizers hematoporphyrin derivatives Photofrin ® benzoporphyrinderivatives Npe6 tin etioporphyrin (SnET2) pheoboride-abacteriochlorophyll-a naphthalocyanines phthalocyanines zincphthalocyanines Radiation X-ray ultraviolet light gamma radiationvisible light infrared radiation microwave radiation

Second agents glucocorticoids, the invention for treatment of autoimmunediseases are referred to as immunosuppressive agents, which act tosuppress or mask the immune system of the individual being treated.Immunosuppressive agents include, for example, non-steroidalanti-inflammatory drugs (NSAIDs), analgesics, glucocorticoids,disease-modifying antirheumatic drugs (DMARDs) for the treatment ofarthritis, or biologic response modifiers. Compositions in the DMARDdescription are also useful in the treatment of many other autoimmunediseases aside from RA.

Exemplary NSAIDs are chosen from the group consisting of ibuprofen,naproxen, naproxen sodium, Cox-2 inhibitors such as Vioxx and Celebrex,and sialylates. Exemplary analgesics are chosen from the groupconsisting of acetaminophen, oxycodone, tramadol of proporxyphenehydrochloride. Exemplary glucocorticoids are chosen from the groupconsisting of cortisone, dexamethasone, hydrocortisone,methylprednisolone, prednisolone, or prednisone. Exemplary biologicalresponse modifiers include, but are not limited to, molecules directedagainst cell surface markers (e.g., CD4, CD5, etc.), cytokineinhibitors, such as the TNF antagonists (e.g. etanercept (Enbrel),adalimumab (Humira) and infliximab (Remicade)), chemokine inhibitors andadhesion molecule inhibitors. The biological response modifiers includemonoclonal antibodies as well as recombinant forms of molecules.Exemplary DMARDs include, but are not limited to, azathioprine,cyclophosphamide, cyclosporine, methotrexate, peniciliamine,leflunomide, sulfasalazine, hydroxychloroquine, Gold [oral (auranofin)and intramuscular] and minocycline.

It is contemplated the binding molecule composition and the second agentmay be given simultaneously in the same formulation. Alternatively, theagents are administered in a separate formulation but concurrently, withconcurrently referring to agents given within 30 minutes of each other.

In another aspect, the second agent is administered prior toadministration of the binding molecule composition. Prior administrationrefers to administration of the second agent within the range of oneweek prior to treatment with the antibody, up to 30 minutes beforeadministration of the antibody. It is further contemplated that thesecond agent is administered subsequent to administration of the bindingmolecule composition. Subsequent administration is meant to describeadministration from 30 minutes after antibody treatment up to one weekafter antibody administration.

It is further contemplated that when the binding molecule isadministered in combination with a second agent, wherein the secondagent is a cytokine or growth factor, or a chemotherapeutic agent, theadministration may also include use of a radiotherapeutic agent orradiation therapy. The radiation therapy administered in combinationwith an antibody composition is administered as determined by thetreating physician, and at doses typically given to patients beingtreated for cancer.

The amounts of binding molecule in a given dose will vary according tothe size of the individual to whom the therapy is being administered aswell as the characteristics of the disorder being treated. In exemplarytreatments, it may be necessary to administer about 1 mg/day, about 5mg/day, about 10 mg/day, about 20 mg/day, about 50 mg/day, about 75mg/day, about 100 mg/day, about 150 mg/day, about 200 mg/day, about 250mg/day, about 500 mg/day or about 1000 mg/day. The doses may also beadministered based on weight of the patient, at a dose of about 0.01 toabout 50 mg/kg. In a related embodiment, the binding molecule may beadministered in a dose range of about 0.015 to about 30 mg/kg. In anadditional embodiment, the binding molecule is administered in a dose ofabout 0.015, about 0.05, about 0.15, about 0.5, about 1.5, about 5,about 15 or about 30 mg/kg.

These compositions may be administered in a single dose or in multipledoses. Standard dose-response studies, first in animal models and thenin clinical testing, reveal optimal dosages for particular diseasestates and patient populations.

The administration of the binding molecule composition decreases theB-cell population by at least 20% after a single dose of treatment. Inone embodiment, the B-cell population is decreased by at least about 20,about 30, about 40, about 50, about 60, about 70, about 80, about 90 orabout 100%. B-cell reduction is defined as a decrease in absolute B-cellcount below the lower limit of the normal range. B-cell recovery isdefined as a return of absolute B-cell count to either of the following:70% of subject's baseline value or normal range.

The administration of CD20-specific binding molecules also results inenhanced apoptosis in particular B-cell subsets. Apoptosis refers to theinduction of programmed cell death of a cell, manifested and assessed byDNA fragmentation, cell shrinkage, cell fragmentation, formation ofmembrane vesicles, or alteration of membrane lipid composition asassessed by annexin V staining.

Further, the administration of binding molecule compositions of theinvention results in desired clinical effects in the disease or disorderbeing treated. For example, in patients affected by rheumatoidarthritis, in one aspect the administration improves the patient'scondition by a clinically significant amount [e.g., achieves theAmerican College of Rheumatology Preliminary Detection of Improvement(ACR20)], and/or an improvement of 20% in tender and swollen joint and20% improvement in 3/5 remaining ACR measures (Felson et al., ArthritisRheum. 1995, 38:727-35). Biological measures for improvement in an RApatient after administration of CD37-specific and CD20-specific bindingmolecules include measurement of changes in cytokine levels, measuredvia protein or RNA levels. Cytokines of interest include, but are notlimited to, TNF-α, IL-1, interferons, Blys, and APRIL. Cytokine changesmay be due to reduced B cell numbers or decreased activated T cells. InRA patients, markers relevant to bone turnover (bone resorption orerosion) are measured before and after administration of CD20-specificbinding molecules. Relevant markers include, but are not limited to,alkaline phosphatase, osteocalcin, collagen breakdown fragments,hydroxyproline, tartrate-resistant acid phosphatase, and RANK ligand(RANKL). Other readouts relevant to the improvement of RA includemeasurement of C reactive protein (CRP) levels, erythrocytesedimentation rate (ESR), rheumatoid factor, CCP (cyclic citrullinatedpeptide) antibodies and assessment of systemic B cell levels andlymphocyte count via flow cytometry. Specific factors can also bemeasured from the synovium of RA patients, including assessment of Bcell levels in synovium from synovium biopsy, levels of RANKL and otherbone factors and cytokines set out above.

In a related aspect, the effects of combination administration on otherdiseases is measured according to standards known in the art. Forexample, it is contemplated that Crohn's disease patients treatedaccording to the invention achieve an improvement in Crohn's DiseaseActivity Index (CDAI) in the range of about 50 to about 70 units,wherein remission is at 150 units (Simonis et al, Scand. J Gastroent.1998, 33:283-8). A score of 150 or 200 is considered normal, while ascore of 450 is considered a severe disease score. It is further desiredthat administration of the CD37-specific and CD20-specific bindingmolecules results in a reduction in perinuclear anti-neutrophil antibody(pANCA) and anti-Saccharomyces cervisiae antibody (ASCA) in individualsaffected by inflammatory bowel disease.

It is further contemplated that adult and juvenile myositis patientstreated according to the invention achieve an improvement in core set ofevaluations, such as 3 out of 6 of the core set measured improved byapproximately 20%, with not more than 2 of the core measurements worseby approximately 25% (see Rider et al., Arthritis Rheum. 2004,50:2281-90).

It is further contemplated that SLE patients treated according to theinvention achieve an improvement in Systemic Lupus Activity Measure(SLAM) or SLE Disease Activity Index (SLEDAI) score of at least 1 point(Gladman et al, J Rheumatol 1994, 21:1468-71) (Tan et al., ArthritisRheum. 1982, 25:1271-7). A SLAM score of >5, or SLEDAI score >2 isconsidered clinically active disease. A response to treatment may bedefined as improvement or stabilization over the in 2 disease activitymeasures (the SLE Disease Activity Index [SLEDAI] and the Systemic LupusActivity Measure) and 2 quality of life measures (patient's globalassessment and the Krupp Fatigue Severity Scale) (Petri et al.,Arthritis Rheum. 2004, 50:2858-68.) It is further contemplated thatadministration of the binding molecule to SLE patients results in areduction in anti-double-stranded DNA antibodies. Alternatively,improvement may be gauged using the British Isles Lupus Assessment GroupCriteria (BILAG).

It is further contemplated that multiple sclerosis patients treatedaccording to the invention achieve an improvement in clinical score onthe Kurtzke Expanded Disability status scale (EDSS) (Kurtzke, F.,Neurology 1983, 33:1444-52) of at least 0.5, or a delay in worsening ofclinical disease of at least 1.0 on the Kurtzke scale (Rudick et al.,Neurology 1997, 49:358-63).

It is further contemplated that patients suffering from IIM receivingCD37-specific and CD20-specific binding molecules achieve a reduction inat least one of five criteria set out in the Idiopathic InflammatoryMyopathy Criteria (IIMC) assessment (Miller, F., supra). It is furthercontemplated that administration to IIM patients results in a reductionin IIM associated factors selected from the group consisting of creatinekinase (CK), lactate dehydrogenase, aldolase, C-reactive protein,aspartate aminotransferase (AST), alanine aminotransferase (ALT), andantinuclear autoantibody (ANA), myositis-specific antibodies (MSA), andantibody to extractable nuclear antigens. Alternatively, patients meet 3out of 6 of the criteria set out in Rider et al., Arthritis Rheum.,50(7):2281-2290 (2004), with worsening in no more than 2 criteria.

In some embodiments, patients suffering from a B cell cancer receivetreatment according to the invention and demonstrate an overallbeneficial response to the treatment, based on clinical criteriawell-known and commonly used in the art, and as described below, such asa decrease in tumor size, decrease in tumor number and/or an improvementin disease symptoms.

Exemplary clinical criteria are provided by the U.S. National CancerInstitute (NCI), which has divided some of the classes of cancers intothe clinical categories of “indolent” and “aggressive” lymphomas.Indolent lymphomas include follicular cell lymphomas, separated intocytology “grades,” diffuse small lymphocytic lymphoma/chroniclymphocytic leukemia (CLL), lymphoplasmacytoid/Waldenstrom'sMacroglobulinemia, Marginal zone lymphoma and Hairy cell leukemia.Aggressive lymphomas include diffuse mixed and large cell lymphoma,Burkitt's lymphoma/diffuse small non-cleaved cell lymphoma,Lymphoblastic lymphoma, Mantle cell lymphoma and AIDS-related lymphoma.In some cases, the International Prognostic Index (IPI) is used in casesof aggressive and follicular lymphoma. Factors to consider in the IPIinclude Age (<60 years of age versus >60 years of age), serum lactatedehydrogenase (levels normal versus elevated), performance status (0 or1 versus 2-4) (see definition below), disease stage (I or II versus IIIor IV), and extranodal site involvement (0 or 1 versus 2-4). Patientswith 2 or more risk factors have less than a 50% chance of relapse-freeand overall survival at 5 years.

Performance status in the aggressive 1P1 is defined as follows:

Grade Description: 0 Fully active, able to carry on all pre-diseaseperformance without restriction; 1 Restricted in physically strenuousactivity but ambulatory and able to carry out work of a light orsedentary nature, e.g., light house work, office work; 2 Ambulatory andcapable of all selfcare but unable to carry out any work activities, upto and about more than 50% of waking hours; 3 Capable of only limitedselfcare, confined to bed or chair more than 50% of waking hours; 4Completely disabled, unable to carry on any selfcare, totally confinedto bed or chair; and, 5 Dead. (See., The International Non-Hodgkin'sLymphoma Prognostic Factors Project. A predictive model for aggressivenon-Hodgkin's lymphoma. N Engl J Med. 329:987-94, 1993)

Typically, the grade of lymphoma is clinically assessed using thecriterion that low-grade lymphoma usually presents as a nodal diseaseand is often indolent or slow-growing. Intermediate- and high-gradedisease usually presents as a much more aggressive disease with largeextranodal bulky tumors.

The Ann Arbor classification system is also used to measure progressionof tumors, especially non-Hodgkins lymphomas. In this system, stages I,II, III, and IV of adult NHL can be classified into A and B categoriesdepending on whether the patient has well-defined generalized symptoms(B) or not (A). The B designation is given to patients with thefollowing symptoms: unexplained loss of more than 10% body weight in the6 months prior to diagnosis, unexplained fever with temperatures above38° C. and drenching night sweats. Definitions of the stages are asfollows: Stage I-involvement of a single lymph node region or localizedinvolvement of a single extralymphatic organ or site. StageII-involvement of two or more lymph node regions on the same side of thediaphragm or localized involvement of a single associated extralymphaticorgan or site and its regional lymph nodes with or without other lymphnode regions on the same side of the diaphragm. Stage IV-involvement oflymph node regions on both sides of the diaphragm, possibly accompanyinglocalized involvement of an extralymphatic organ or site, involvement ofthe spleen, or both. Stage IV-disseminated (multifocal) involvement ofone or more extralymphatic sites with or without associated lymph nodeinvolvement or isolated extralymphatic organ involvement with distant(non-regional) nodal involvement. For further details, see TheInternational Non-Hodgkin's Lymphoma Prognostic Factors Project: Apredictive model for aggressive non-Hodgkin's lymphoma, New England J.Med. (1993) 329:987-994.

In one aspect, a therapeutic effect of the methods according to theinvention is determined by the level of response, for example a partialresponse is defined as tumor reduction to less than one-half of itsoriginal size. A complete response is defined as total elimination ofdisease confirmed by clinical or radiological evaluation. In oneembodiment, the individual receiving treatment according to theinvention demonstrates at least a partial response to treatment.

According to the Cheson criteria for assessing NHL developed incollaboration with the National Cancer Institute (Cheson et al., J ClinOncol. 1999, 17:1244; Grillo-Lopez et al., Ann Oncol. 2000, 11:399-408),a complete response is obtained when there is a complete disappearanceof all detectable clinical and radiographic evidence of disease anddisease-related symptoms, all lymph nodes have returned to normal size,the spleen has regressed in size, and the bone marrow is cleared oflymphoma.

An unconfirmed complete response is obtained when a patient showscomplete disappearance of the disease and the spleen regresses in size,but lymph nodes have regressed by more than 75% and the bone marrow isindeterminate. An unconfirmed complete response meets and exceeds thecriteria for partial response. An overall response is defined as areduction of at least 50 percent in overall tumor burden.

Similar criteria have been developed for various other forms of cancersor hyperproliferative diseases and are readily available to a person ofskill in the art. See, e.g., Cheson et al., Clin Adv Hematol Oncol.2006, 4:4-5, which describes criteria for assessing CLL; Cheson et al.,J Clin Oncol. 2003, 21:4642-9, which describes criteria for AML; Chesonet al., Blood 2000, 96:3671-4, which describes criteria formyelodysplastic syndromes.

In another aspect, a therapeutic response in patients having a B cellcancer is manifest as a slowing of disease progression compared topatients not receiving therapy. Measurement of slowed diseaseprogression or any of the above factors may be carried out usingtechniques well-known in the art, including bone scan, CT scan, galliumscan, lymphangiogram, MRI, PET scans, ultrasound, and the like.

It will also be apparent that dosing may be modified if traditionaltherapeutics are administered in combination with therapeutics of theinvention.

As an additional aspect, the invention includes kits which comprise oneor more compounds or compositions useful in the methods of the inventionpackaged in a manner which facilitates their use to practice methods ofthe invention. In a simplest embodiment, such a kit includes a compoundor composition described herein as useful for practice of a method ofthe invention packaged in a container such as a sealed bottle or vessel,with a label affixed to the container or included in the package thatdescribes use of the compound or composition to practice the method ofthe invention. Preferably, the compound or composition is packaged in aunit dosage form. The kit may further include a device suitable foradministering the composition according to a preferred route ofadministration or for practicing a screening assay. The kit may includea label that describes use of the binding molecule composition(s) in amethod of the invention.

The present invention also comprises articles of manufacture. Sucharticles comprise CD37-specific binding molecules or CD37-specific andCD20-specific binding molecules, optionally together with apharmaceutical carrier or diluent, and at least one label describing amethod of use of the binding molecules according to the invention. Sucharticles of manufacture may also optionally comprise at least one secondagent for administration in connection with the binding molecules.

The present invention also calls for use of a composition comprising aCD37-specific binding molecule or CD37-specific and CD20-specificbinding molecules in the manufacture of a medicament for the treatmentor prophylaxis of a disease involving aberrant B-cell activity.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1A diagrams the structure of the TRU-016 molecule; FIG. 1B showsthe results of SDS-PAGE analysis, demonstrating that the expressedprotein migrates at a Mr of approximately 110 kDa under nonreducingconditions, and approximately 52 kDa when subjected to reducingconditions; and FIG. 1C shows that the TRU-016 molecule demonstrateshigh level, specific binding to human peripheral blood B lymphocytes,and a much lower level of binding to other subpopulations of cells inthe non-B cell lymphocyte gate (CD19 negative population) when analyzedby flow cytometry.

FIG. 2A-E shows binding inhibition by different CD37 targeted reagents.

FIG. 3A demonstrates FITC C1q binding to TRU-016 molecular formsincubated with Ramos B Cells in normal human serum with and withoutcobra venom factor (CVF); FIG. 3B shows CDC activity of TRU-016molecular forms incubated with Ramos B Cells in normal human serum withand without CVF; and FIG. 3C shows CDC activity of TRU-016 molecularforms incubated with Ramos B cells and human or rabbit complement.

FIG. 4 shows the protein A purified material analyzed by SEC HPLC (FIG.4A) and HPLC size exclusion chromatography (SEC) traces obtained fromGPC purification of the TRU-016 (FIG. 4B), plotting absorbance versusretention time for the different fractions collected. FIG. 4C shows theHPLC SEC traces obtained from HMW or A2 pools

FIG. 5A shows the binding properties of SEC fractions; FIG. 5B shows theCDC activity of SEC fractions; and FIG. 5C shows the ADCC activity ofSEC fractions.

FIG. 6 shows the CDC activity of TRU-015, rituxan, TRU-016, or acombination thereof on Ramos B cells.

FIG. 7 shows that the effect of TRU-016 on CDC activity of TRU-015 onDHL-4 B cells.

FIG. 8 shows the effect of TRU-016 on the CDC activity of TRU-015 andrituxan.

FIG. 9 shows the effect of TRU-016 on TRU-015 in a CDC assay.

FIG. 10 shows the effect of TRU-016 on rituxan in a CDC assay.

FIG. 11 shows the interaction of TRU-015 and TRU-016 in an ADCC assayusing BJAB cells.

FIG. 12 shows the interaction of TRU-015 and TRU-016 in an ADCC assayusing Daudi cells.

FIG. 13 shows the interaction of TRU-015 and TRU-016 in an ADCC assayusing Ramos cells.

FIG. 14 shows the effect of rituxan, TRU-016, and a combination thereofon the specific killing of BJAB cells.

FIG. 15 shows the effect of rituxan, TRU-016, and a combination thereofon the specific killing of BJAB cells.

FIG. 16 shows the effect of TRU-015, TRU-016, and a combination thereofon the specific killing of BJAB cells.

FIG. 17 shows the effect of TRU-015, TRU-016, and a combination thereofon the specific killing of BJAB cells.

FIG. 18A-D shows that TRU-016 dimer forms do not mediate CDC alone, butpotentiate the CDC activity of Rituximab in vitro.

FIG. 19A-B demonstrates that protein A purified TRU-016 inducesapoptosis of Ramos and Daudi cells, while dimer forms requirecrosslinking.

FIGS. 20A, 20B, and 20C show that TRU-016 preferentially depletes normalB cells from PBMC cultures. FIGS. 20A and 20B show the percent CD19positive (FIG. 20A) or CD40 positive (FIG. 20B) cells following a 48 or72 hour incubation with TRU016 or rituximab. FIG. 20C shows the percentreduction from the original number of lymphocytes expressing theindicated CD antigen (i.e. CD19, CD40 or CD3 positive) after incubationof PBMCs with TRU-016 (at 1 μg/ml) for 24 and 72 hours.

FIG. 21 demonstrates the efficacy of TRU-016 compared to huIgG, rituxan,and the combination treatment of TRU-016 and rituxan on tumor volume inanimals.

FIGS. 22A and B shows that TRU-016 dimer forms exhibit significantanti-tumor activity, as measured by effect on tumor volume and percentsurvival in a mouse xenograft tumor model.

FIGS. 23A, 23B, 23C, and 23D demonstrate that TRU-016 dimers do notaugment CDC activity resulting from treatment with MHCII (FIG. 23A),CD19 (FIG. 23B), CD45 (FIG. 23C), or CD80/86 (FIG. 23D; treatment withthe CD80/86 specific reagent CTLA4Ig is shown) specific reagents.

FIG. 24 shows the percent survival of mice with Ramos tumors (up to 90days) after treatment with TRU-016, rituximab, or a combination thereof.

FIGS. 25 and 26 show the percent survival of mice with Daudi tumors (upto 90 days) after treatment with TRU-016 or rituximab.

FIG. 27 shows that TRU-016 effectively reduced relative cell viabilityin cells treated with fludarabine, thereby potentiating the cytotoxiceffect of fludarabine

FIG. 28 shows that TRU-016 induced greater cell toxicity than herceptinor rituximab in rituximab-resistant cell lines.

FIG. 29 shows that TRU-016 induced tyrosine phosphorylation in CD19+primary CLL B cells.

FIG. 30A shows the consensus amino acid sequence of humanized TRU-016construct no. 019001 (SEQ ID NO: 6) and TRU-016 (SEQ ID NO: 2) withKabat numbering;

FIG. 30B shows amino acid sequence alignments of three humanized TRU-16constructs (019001, 019008, and 109009).

FIG. 31 shows the DNA and amino acid sequence alignments of threehumanized constructs of TRU-016 (019001, 019041, and 019044).

FIG. 32A-32D shows the FASTA formatted sequence alignments of the samethree humanized constructs of TRU-016 (019001, 019041, and 019044).

EXAMPLES

Additional aspects and details of the invention will be apparent fromthe following examples, which are intended to be illustrative ratherthan limiting. Example I describes the production of a CD37-specificbinding molecule; Example 2 demonstrates that TRU-016 and variousCD37-specific antibodies recognize the same or overlapping epitopes;Example 3 shows that TRU-016 is deficient in binding C1q and activatingthe classical complement activation pathway; Example 4 demonstratesactivity and binding of TRU-016 multimers; Example 5 describes theproduction of a CD20-specific binding molecule; Example 6 shows thatcombinations of TRU-016 with TRU-015 or rituxan synergistically increaseapoptosis in B cells; Example 7 shows that combinations of TRU-016 withCD20-specific antibodies or SMIPs synergistically increase CDC; Example8 demonstrates that TRU-016 augments the ADCC and the CDC activity ofCD20-specific antibodies and SMIPS; Example 9 demonstrates that TRU-016induces apoptosis in B cells; Example 10 shows that combinations of aCD37-specific SMIP with a CD20-specific antibody synergistically reducetumor volume in a murine tumor xenograft model; Example 11 shows that aCD37-specific SMIP alone also reduces tumor volume in a murine tumorxenograft model; Example 12 demonstrates that TRU-016 does not affectthe CDC activity of other B cell surface receptors; Example 13demonstrates that TRU-016 does not augment the CDC activity of varioustargeted receptors, including MHCII, CD19, CD80/86, and CD40; Example 14provides additional data showing that TRU-016 increases survival in vivoin mice with tumors; Example 15 demonstrates that TRU-016 potentiatesfludarabine-induced cell death in CLL cells in vitro; Example 16 showsthat TRU-016 induces direct cytotoxicity in rituximab-resistant cells;Example 17 shows that TRU-016 induces tyrosine phosphorylation in CD19+primary CLL B cells; and Example 18 provides humanized TRU-016molecules.

Example 1 Production of a CD37-Specific Binding Molecule

CD37-specific SMIPs are described in co-owned U.S. application Ser. No.10/627,556 and U.S. Patent Publication Nos. 2003/133939, 2003/0118592and 2005/0136049. An exemplary SMIP, TRU-016, is produced as describedbelow.

TRU-016 [G28-1 scFv VH11S(SSC-P) H WCH2 WCH3] is a recombinant singlechain protein that binds to the CD37 antigen. The binding domain wasbased on the G28-1 antibody sequence previously disclosed in the patentpublications listed in the preceding paragraph, which disclosure isincorporated herein by reference. The binding domain is connected to theeffector domain, the CH2 and CH3 domains of human IgG1, through amodified hinge region. TRU-016 exists as a dimer in solution and thedimer has a theoretical molecular weight of approximately 106,000daltons.

Total RNA from the G28-1 hybridoma was isolated using Trizol RNA (Gibco)reagent according to the manufacturers instructions. cDNA was preparedusing 51 μg RNA, random primers and Superscript II Reverse Transcriptase(GIBCO BRL). The variable domains were cloned using pools of degenerateprimers for the different murine VK or VH gene families. The variabledomains from the G28-1 hybridoma were cloned into PCR 2.1 TOPO cloningvectors (Invitrogen) and DNA from transformants with correct sizeinserts was sequenced. Heavy and light chain variable regions fromcorrect clones were then used as templates for sewing PCR amplificationof a G28-1 scFv joined together in the VL-VH orientation with a 15 as(gly4ser)3 linker. The anti-CD37 scFv was attached to a modified humanIgG1 hinge, CH2, and CH3 domains (see FIG. 1A). In order to ensureadequate expression by mammalian cells, modifications of the variableregions were selected that allowed significant increases in expressionby mammalian cells. Specifically, a leucine was changed to a serine atposition 11 of the scFV. The predicted mature peptide is 473 amino acidslong.

The polynucleotide sequence encoding TRU-016 and the amino acid sequenceof TRU-016 are respectively set out in SEQ ID NOs: 1 and 2.

TRU-016 was produced by recombinant DNA technology in a Chinese hamsterovary (CHO) mammalian cell expression system. Transfected CHO cells thatproduce the SMIP were cultured in a bioreactor using proprietary media.

TRU-016 SMIPs were purified from CHO culture supernatants by Protein Aaffinity chromatography. Using dPBS, a 50 mL rProtein A FF sepharosecolumn (GE Healthcare rProtein A Sepharose FF, Catalog #17-0974-04) wasequilibrated at 5.0 mls/min (150 cm/hr) for 1.5 column volumes (CV). Theculture supernatant was loaded to the rProtein A Sepharose FF column ata flow rate of 1.7 mls/min using the AKTA Explorer 100 Air (GEhealthcare AKTA Explorer 100 Air, Catalog #18-1403-00), capturing therecombinant TRU-016. The column was washed with dPBS for 5 ColumnVolumes (CV), then 1.0 M NaCl, 20 mM Sodium Phosphate, pH 6.0, and thenwith 25 mM NaCl, 25 mM NaOAc, pH 5.0. These washing steps removednonspecifically bound CHO host cell proteins from the rProtein A columnthat contribute to product precipitation after elution.

The recombinant TRU-016 was eluted from the column with 100 mM Glycine,pH 3.5. 10 mL fractions of the eluted product were recovered and theeluted product was then brought to pH 5.0 with 20% of the eluted volumeof 0.5 M 2-(N-Morpholino)ethanesulfonic acid (MES) pH6.0. This elutedproduct was prepared for GPC purification by concentration of the sampleto approximately 25 mg/mL TRU-016 and then filter sterilized inpreparation for GPC purification.

Purified protein was then subjected to GPC size exclusion chromatography(SEC) to achieve further purification of the TRU-016 (dimer) moleculefrom higher molecular weight aggregates. Using dPBS, an XK 50/100 column(GE healthcare XK 50/100 empty chromatography column, Catalog#18-8753-01) containing 1 L of Superdex 200 FF sepharose wasequilibrated at 12.6 mls/min (38 cm/hr) for 1.5 column volumes (CV). Amaximum volume of 54 mls (3% CV) of sample was applied to the column.The column continued to run at 12.6 ml/min and the eluted protein wasfractionated in 40 mL fractions. Each fraction was analyzed for productquality using an analytic HPLC, and the eluted fractions were pooledfor >95% POI (non-aggregated) TRU-016. This resultant pool was filtersterilized at 0.22 μm. The material was then concentrated and formulatedwith 20 mM sodium phosphate and 240 mM sucrose, with a resulting pH of6.0. The composition is filtered before filling into glass vials at aconcentration of 10 mg/mL. Each glass vial contains 5 mL of TRU-016 (50mg/vial).

TRU-016 protein was also subject to SDS-PAGE analysis on 4-20% NovexTris-glycine gels (Invitrogen, San Diego, Calif.). Samples were loadedusing Novex Tris-glycine SOS sample buffer (2×) under reducing (additionof 1/10 volume NuPAGE sample reducing agent) or non-reducing conditionsafter heating at 95° C. for 3 minutes, followed by electrophoresis at150V for 90 minutes. Electrophoresis was performed using 1× NovexTris-Glycine SDS Running Buffer (Invitrogen). Gels were stained afterelectrophoresis in Coomassie SOS PAGE R-250 stain for 30 minutes withagitation, and destained for at least one hour. The predicted molecularweight of the mature peptide is 51.5 kDa. Under reducing conditions,fusion protein migrates at the expected molecular weight. Undernon-reducing conditions, the molecule migrates at approximately 150 kDa(FIG. 1B).

Experiments were also performed to determine that the bindingspecificity of the parent antibody to the CD37 cell surface receptor ispreserved in TRU-016. Human PBMCs were isolated over LSM densitygradients and incubated with unconjugated TRU-016 and PE-conjugatedanti-human CD19. Cells were washed and incubated with 1:100 FITC GAH IgG(Fc specific) for 45 minutes on ice. Cells were washed and analyzed bytwo-color flow cytometry on a FACsCalibur instrument using Cell Questsoftware. Cells were gated for B lymphocytes or non-B lymphocytes byCD19 staining.

With increasing concentrations of TRU-016, the FITC signal on the Blymphocyte (CD19 positive gate) increased rapidly from 0.01-1.0 μg/ml,until it reached saturation at approximately 1 μg/mL or a meanfluorescence intensity (MFI) of 1000. In contrast, the staining of thenon-B lymphocyte population is detectable, but very low, and increasesslowly with increasing concentration of scFvIg. Thus, the stainingpattern of the G28-1 murine monoclonal antibody is preserved withTRU-016 (FIG. 1C).

The CD37-binding molecules according to the invention describestructures (binding domains derived from antibodies, hinge variants,CH2CH3 regions being the same or different, and various isotypes).

Example 2 TRU-016 and Various CD37-Specific Antibodies Bind the Same orOverlapping Epitopes on CD37

Experiments were performed to identify the CD37 epitope bound by TRU-016and other previously described CD37-specific antibodies.

Unconjugated MB371 (#555457) and FITC-conjugated MB371 (#555456) wereobtained from BD Pharmingen (San Jose, Calif.), FITC-conjugated BL14(#0457) from Immunotech/Beckman Coulter (Fullerton, Calif.),FITC-conjugated NMN46 (#RDI-CBL 136FT) and unconjugated NMN46 (#RDI-CBL136) from RD1 (Flanders, N.J.), FITC-conjugated IPO24 (#186-040) andunconjugated IPO-24 (#186-020) from Ancell Corporation (Bayport, Minn.),F1TC-conjugated HH1 (#3081) and unconjugated HH1 (#3080) from DiaTec.Com(Oslo, Norway) and FITC-conjugated WR17 (YSRTMCA483F) and unconjugatedWR17 (YSRTMCA483S) from Accurate Chemical & Scientific (Westbury, N.Y.).TRU-016 protein was produced as described in Example 1.

TRU-016 was conjugated to FITC at Trubion using a Molecular ProbesFluororeporter FITC Labeling Kit (F6434) according to manufacturer'sinstructions as follows: TRU-016 protein peak of interest (POI) at 13.5mg/mL was adjusted to 5 mg/mL with PBS. 1 mg (200 ul) was added to kittubes with a stirbar, and 1M NaHCO3 (adjusted to pH 8.5 with 6N NaOH),was added to a final concentration of 0.1M. 50 ul DMSO was added to 370ug of FITC and was added to the tubes at molar ratios of 15, 20, 30 and40 FITC:protein using the following formula to determine the ul of FITCto add: [ul of FITC solution to add=5 mg/mL protein×0.2 mL×389×100×desired molar ratio/Molecular weight of TRU-016 (110,000)].

Reactions were shielded from light and stirred continuously for 75minutes at room temperature. Reactions were added to spin columnsprepared as described in the kit and spun at 1100 g for 5 minutes tobuffer exchange into PBS with azide and remove unconjugated FITC. The ODat 280 nM and 494 nM was determined with 2 ul drops on the Nanodrop; theextinction coefficient for TRU-016 was experimentally determined forthis instrument by reading dilutions of the starting unconjugated SMIP,the concentration of each of the conjugates was 4.25 mg/ml and thefollowing FITC:protein rations were determined: 2.7 FITC/TRU-016 at aratio of 15; 3.7 FITC/TRU-016 at a ratio of 20; 4.4 FITC/TRU-016 at aratio of 30; and 5.1 FITC/TRU-016 at a ratio of 40.

BSA was added to 3 mg/mL to help stabilize the protein. Binding of eachfraction was assessed at dilutions ranging from 100-24,300× on Ramos and3200-25,600 on human PBMC. All bound, but the MR30 ratio was chosen forfurther use since it gave a high MFI that was well maintained over thetitration range used, indicating that binding avidity was least affectedin this reaction.

FITC labeled antibody conjugates were titrated from 10 μg/mL to 10 pg/mLin an initial binding study to determine the optimal amounts to use inthe blocking studies. The level chosen was just below saturatingamounts, and was kept constant in the subsequent assays, while levels ofblocking antibody were increased over a 10-fold range. Data were plottedas percent of maximal binding versus concentration of blocking antibody,so that higher levels indicate less efficient blocking, while lowerlevels indicate more efficient blocking activity. All of the antibodiestested showed blocking activity of the maximal binding observed withoutunlabeled reagents (FIG. 2).

BJAB-cells, a B lymphoblastoid B-cell line, (courtesy of Ed Clark,University of Washington) were then stained with a panel of variousclones of anti-CD37 MAbs, including MB371, BL14, NMN46, IPO24, HH1,WR17, and the TRU-016 SMIP.

For competitive binding assays, 2.5×10⁵ BJAB cells were incubated in96-well V-bottom plates in staining media (PBS with 2% mouse sera) withthe FITC-conjugated anti-CD37 MAbs at 1.25 μg/mL in the presence ofunconjugated anti-CD37 MAb at the indicated concentrations (2.5, 1.25,0.6, or 0.3 μg/ml) or staining media for 45 minutes on ice in the dark.Blocking antibodies and FITC labeled antibody conjugates were added toreactions prior to addition of cells. The cells were then washed 2½times with PBS and fixed with 1% paraformaldehyde (#19943, USB,Cleveland, Ohio). The cells were analyzed by flow cytometry using aFACsCalibur instrument and CellQuest software (BD Biosciences, San Jose,Calif.).

For FACs cross blocking assays, 2.5×10⁵ BJAB cells were incubated in96-well V-bottom plates in staining media (PBS with 2% mouse sera) inthe presence of unconjugated anti-CD37 MAb at 5 μg/mL staining media for45 minutes at room temperature in the dark. F1TC-conjugated anti-CD37MAbs were then added to a final concentration of 2 μg/ml, resulting in adilution of the unlabelled reagents to 3.3 μg/ml. The reactions werethen further incubated for 45 minutes at room temperature in the dark.Reactions were washed 2.5 times with PBS and fixed in 1%paraformaldehyde in PBS (#19943, USB, Cleveland, Ohio). Cells wereanalyzed by flow cytometry on a FACsCalibur instrument using Cell Questsoftware (BD Biosciences, San Jose, Calif.).

For cell binding assays, cells were suspended in PBS (#14040-133,Gibco/Invitrogen, Grand Island N.Y.) containing 2% FBS (#16140-071,Gibco/Invitrogen, Grand Island, N.Y.), (staining media) at aconcentration of approximately 4×10⁶ cells/mL. Cells were then platedand test samples, diluted in staining media, were then added 1:1 to thefinal designated concentrations. Reactions were incubated for 45 minuteson ice. Samples were centrifuged and washed 2 times with PBS. FITC goatanti-human IgG (#H10501, CalTag, Burlingame Calif.) was added at a finaldilution of 1:50, and incubated 45 minutes on ice. Samples werecentrifuged, washed in PBS, then fixed in 200 μl 1% paraformaldehyde inPBS (#19943, USB, Cleveland, Ohio). Cells were analyzed by flowcytometry on a FACs Calibur instrument using Cell Quest software (BDBiosciences, San Jose, Calif.).

Each antibody showed dose dependent inhibition of binding, indicatingthat all the molecules tested bind to an identical or closely relatedepitope. A different potency for inhibition of binding was observed foreach antibody. TRU-016 SMIP had the highest level of blocking activityof all molecules tested, while HH1 gave an intermediate level ofblocking activity, and WR17, IPO24 blocked better than MB371; but showedless effective blocking than the other two unlabeled molecules (FIG. 2).

In addition to analysis of blocking activity, a similar series ofexperiments was performed in which various CD37 targeted antibodies weretested for their ability to compete with one another for binding to theCD37 receptor. The results from these experiments, like results obtainedin the blocking studies for all the molecules tested, indicated that thevarious CD37 targeted antibodies and TRU-016 have the same or closelyoverlapping epitopes.

Example 3 TRU-016 is Deficient in Binding C1q and Activating theClassical Complement Activation Pathway

Experiments were performed to explore why the TRU-016 dimer peak failsto mediate significant levels of complement dependent killing of B celltargets. One possibility was that TRU-016 dimer shows reduced binding tocomponents of the complement cascade relative to normal human IgG1antibody. Thus, experiments were performed to determine if TRU-016activates the classical complement activation pathway by looking forTRU-016 binding to C1q. C1q, is a subunit of the C1 enzyme complex thatactivates the serum complement system, and is the recognition componentof the classical complement activation pathway.

C1q binding studies were performed as previously described (Cragg etal., Blood 2004, 103:2738-2743). Briefly, Ramos B-cells in Iscoves media(#12440-053, GibcoInvitrogen, Grand island, NY) with no serum wereplated in 96-well V bottom plates at 5×10⁵/well in 100 μl. Cells wereincubated with reagents for 15 minutes at 37° C., and normal human serum(NHS, #A113, Quidel Corp., San Diego, Calif.) diluted in Iscoves wasthen added at a volume of 50 μl to each well for a final concentrationof 10, 5, 2.5, or 1.25% human serum. Fifty μl of media was added to thecontrol well. For cobra venom factor (CVF) experiments, CVF was added tohuman serum complement samples at 20 Units CVF/mL of serum for 90minutes at 37° C. prior to addition of serum to complement assays, andthe dilution of serum by CVF accounted for when making sample dilutions.

The cells plus complement source were incubated for an additional 5minutes at 37° C., and washed 2 times with cold PBS (#14040-133,Gibco/Invitrogen, Grand Island, N.Y.) via centrifugation and resuspendedin 100 μl of PBS. Fifty μl from each well was transferred to a secondplate for second step control staining. Both plates were stained for 15minutes in the dark on ice with either FITC sheep anti-HU C1q(#C7850-06A, US Biological, Swampscott, Mass.) or RTC Sheep IgG(#11904-56P, US Biological, Swampscott, Mass.). Samples were washed,resuspended in cold PBS, and read immediately on a FACsCalibur flowcytometer and analyzed with Cell Quest software (Becton Dickinson, SanJose, Calif.).

FITC C1q does not bind well to any subfractions of SEC purified TRU-016,although the higher molecular weight (HMW) or A2 aggregate fraction doesshow more binding than the other forms (FIG. 3A). In contrast, Rituxanshowed a significant level of C1q binding, particularly at lower levelsof NHS. The presence of CVF failed to completely block this binding,although the MFI levels are reduced significantly compared to mediaalone.

CDC assays were then performed to compare the ability of the differentsubfractions of the TRU-016 purified forms and Rituxan to mediate cellkilling in the presence or absence of CVF and human serum complement(FIG. 3B). CDC assays were performed using propidium iodide staining todiscriminate between live and dead cells after incubations of targetcells with antibody, fusion proteins, ascites fluid, TRU-016 molecularforms, or media, and a source of complement such as human serum.Briefly, 3×10⁵ Ramos B-cells were pre-incubated with test reagents for30-45 minutes at 37° C. prior to addition of complement. The preboundsamples were centrifuged, washed, and resuspended in Iscoves with humanserum (#A113, Quidel, San Diego, Calif.) at the indicatedconcentrations, then incubated for 90 minutes at 37° C. Samples werewashed and propidium iodide (#P-16063, Molecular Probes, Eugene, Oreg.)was added to a final concentration of 0.5 μg/ml in PBS. The cells wereincubated with the propidium iodide for 15 minutes at room temperaturein the dark and then analyzed by flow cytometry on a FACsCaliburinstrument with CellQuest software (Becton Dickinson).

Cell killing mediated by both the A2 fraction of TRU-016 and Rituxan wassignificantly reduced in the presence of CVF despite its failure tocompletely block C1q binding (FIG. 3B).

Human and rabbit complement were then compared for their CDC activity inthe presence of the TRU-016. The CDC activity of TRU-016 molecular formsincubated with Ramos B cells and human or rabbit complement was measured(FIG. 3C). Ramos B cells were added to wells in serum free media.Rituxan or the dimer, HMW A2, or pA fractions of TRU-016 were added tocells to give a final concentration of 10 μg/ml, and incubated for 15minutes at 37° C., prior to washing 1.5× in serum free media andaddition of normal human serum (NHS) or rabbit complement (Pelfreez) at10, 5, or 2.5%. Cells plus complement source were incubated 90 minutesat 37° C. Cells were washed once with cold PBS and propidium iodide(Molecular Probes #P3566) added to a final concentration of 0.5 μg/mL incold PBS. Cells with PI were incubated in the dark at RT for 15 minutesand analyzed by flow cytometry.

The origin of the complement fraction affects the CDC results obtained(FIG. 3C). Rabbit complement mediated higher levels of CDC than humancomplement in the presence of TRU-016 molecular forms. Interestingly,the dimer form of the TRU-016 mediated good CDC using rabbit complement,but very low CDC activity in the presence of human complement.

Example 4 Activity and Binding of TRU-016 Multimers

Experiments were performed to examine the biological activity ofmultimeric forms of TRU-016 (TRU-016 multimers) in solution. First, todetermine the size of TRU-016 fusion protein in solution, protein Apurified material was analyzed by SEC HPLC and revealed that TRU-016exists in multiple forms in solution (FIG. 4).

HPLC size exclusion chromatography (SEC) traces were obtained from GPCpurification of TRU-016, plotting absorbance versus retention time forthe different fractions collected (FIG. 4). TRU-016 was purified fromcell culture supernatants initially by affinity chromatography usingProtein A Sepharose. The recombinant molecule was eluted from the columnwith 100 mM glycine, pH 3.5. 10 mL fractions of the eluted product wererecovered and the eluted product was then brought to pH 5.0 with 20% ofthe eluted volume of 0.5 M 2-(N-Morpholino)ethanesulfonic acid (MES)pH6.0. The eluate was prepared for GPC purification by concentration ofthe sample to approximately 25 mg/mL TRU-016 and then filter sterilizedin preparation for GPC purification. Size exclusion chromatography wasperformed on a GE Healthcare AKTA Explorer 100 Air apparatus, using a GEhealthcare XK column and Superdex 200 preparative grade (GE Healthcare).

The HMW or A2 pools exhibited a retention time of approximately 6.23minutes, while the most prominent form showed a retention time of 8.38minutes. The reference standard used here (pA standard or std) isprotein A purified material containing both dimers and HMW mulitimerforms, as shown in the first panel of FIG. 4. The most prominent form,migrating at a retention time of 8.38 minutes, most likely correspondsto the dimer molecule seen on non-reduced SDS-PAGE, and several minorforms most likely correspond to multimers that associate throughnon-covalent interactions as they are not evident on nonreducingSDS-PAGE. To separate these different forms of TRU-016, materialobtained from protein A sepharose affinity chromatography of culturesupernatants was further purified by GPC and HPLC fractionation toisolate the dimer form (identified as “dimers” or “dimer peak”) fromhigher molecular weight multimers (identified as HMW or A2 aggfraction). Each of these three subfractions was then analyzed separatelyfor functional activity in vitro using binding, ADCC, and CDC assays.

To explore whether the fractions isolated from SEC showed differentbinding properties, each fraction of TRU 016 SEC was tested for bindingto Ramos cells. To determine the binding properties of SEC fractions,cells were suspended in staining media at a concentration ofapproximately 4×10⁶ cells/mL and then plated at 50 μl/well (2×10⁵cells/well) in staining media. Serial dilutions of SEC fractions werethen added to sequential wells, incubated for 45 minutes, washed, andbinding activity was detected using FITC goat anti-human IgG. Sampleswere fixed in 200 μl 1% paraformaldehyde in PBS. Cells were analyzed byflow cytometry on a FACsCalibur instrument using Cell Quest software (BDBiosciences, San Jose, Calif.) (FIG. 5A).

To determine the CDC activity of SEC fractions, cells were suspended at5×10⁵ cells/well in 75 μl IMDM. TRU 016 SEC fractions (75 μl) were addedto the cells at twice the concentrations indicated. Binding reactionswere allowed to proceed for 45 minutes prior to centrifugation andwashing in serum free Iscoves. Cells were resuspended in Iscoves withhuman serum (#A113, Quidel, San Diego, Calif.) at the indicatedconcentrations. The cells were incubated 60 minutes at 37° C., washed,and resuspended in staining media with 0.5 μg/mL propidium iodide (PI,#P-16063, Molecular Probes, Eugene Oreg.). Samples were incubated 15minutes at room temperature in the dark prior to analysis by flowcytometry using a FACsCalibur and CellQuest software (Becton Dickinson)(FIG. 5B).

To determine the ADCC activity of SEC fractions, BJAB, Ramos, and Daudilymphoblastoid B cells (10⁷) cells were labeled with 500 μCi/mL ⁵¹Crsodium chromate for 2 hours at 37° C. in IMDM/10% FBS. PBMCs wereisolated from heparinized, human whole blood by fractionation overLymphocyte Separation Media (LSM, ICN Biomedical) gradients. Reagentsamples were added to RPMI media with 10% FBS and five serial dilutionsfor each reagent were prepared. For combinations, the reagents werepremixed and diluted prior to addition to the wells. The ⁵¹Cr labeledBJAB were added at (2×10⁴ cells/well). The PBMCs were then added at(5×10⁵ cells/well) for a final ratio of 25:1 effectors (PBMC):targets(BJAB). Reactions were set up in quadruplicate wells of a 96 well plate.TRU-016 SEC fractions were added to wells at a final concentrationranging from 10 ng/mL to 20 μg/mL as indicated on the graphs. Each dataseries plots a different SEC fraction at the titration ranges described.Reactions were allowed to proceed for 6 hours at 37° C. in 5% CO₂ priorto harvesting and counting. CPM released was measured on a PackardTopCounNXT from 50 μl dried culture supernatant. Percent specifickilling was calculated by subtracting (cpm [mean of quadruplicatesamples] of sample−cpm spontaneous release)/(cpm maximal release-cpmspontaneous release)×100 (FIG. 5C).

FIG. 5A shows the titration curves of the different SEC fractionsbinding to Ramos cells. All of the fractionated molecules bound to CD37with similar binding curves except at the highest concentrations tested,where the HMW material exhibited better binding (higher fluorescenceintensity) than the pA standard and the dimer peak forms.

Experiments were also performed to determine if the TRU 016 SECfractions exhibited different levels of functional activity such as CDCand ADCC mediated target cell killing. The graph shown in FIG. 5Bindicates that only the purified HMW multimer fraction mediatedsignificant levels of CDC activity against Ramos B cells using humancomplement. The pA standard exhibited some CDC activity at higherconcentrations, while the dimer peak form showed very little or no CDCactivity at all concentrations tested.

ADCC assays were performed on serial dilutions of various TRU-016 sizefractions using labeled BJAB B cells as targets and human PBMC aseffector cells. TRU 016 SEC fractions were present in wells at a finalconcentration ranging from 10 ng/mL to 20 μg/mL as indicated in thegraph shown in FIG. 5C. Each data series plotted a different SECfraction at the titration ranges described. Data were plotted as %specific killing versus protein concentration. All of the SECsubfractions, including the pA standard, HMW or A2 fraction, and dimerpeak, mediated potent, dose-dependent ADCC against BJAB target cells.Similar results were also obtained using Ramos cells as labeled targets(data not shown).

Example 5 Production of a CD20-Specific Binding Molecule

CD20-specific SMIPs are described in co-owned US Patent Publications2003/133939, 2003/0118592 and 2005/0136049. Production of an exemplaryCD20-specific SMIP, TRU-015, is described below.

TRU-015 is a recombinant (murine/human) single chain protein that bindsto the CD20 antigen. The binding domain was based on a publiclyavailable human CD20 antibody sequence. The binding domain is connectedto the effector domain, the CH2 and CH3 domains of human IgG1, through amodified CSS hinge region. TRU-015 exists as a dimer in solution and thedimer has a theoretical molecular weight of approximately 106,000daltons. The nucleotide sequence encoding TRU-015 and the amino acidsequence of TRU-015 are respectively set out in SEQ ID NOs: 3 and 4.

Referring to the amino acid sequence set out in SEQ ID NO: 4, TRU-015comprises the 2e12 leader peptide cloning sequence from amino acids1-23; the 2H7 murine anti-human CD20 light chain variable region with alysine to serine (VHL11S) amino acid substitution at residue 11 in thevariable region, which is reflected at position 34; anasp-gly3-ser-(gly4ser)2 linker beginning at residue 129, with the linkerhaving an additional serine at the end to incorporate the SacIrestriction site for cassette shuffling; the 2H7 murine anti-human CD20heavy chain variable region, which lacks a serine residue at the end ofthe heavy chain region, i.e., changed from VTVSS to VTVS; a human IgG1Fc domain, including a modified hinge region comprising a (CSS)sequence, and wild type CH2 and CH3 domains.

The CHO cells that produce TRU-015 were cultured in a bioreactor usingproprietary media. TRU-015 was purified using a series of chromatographyand filtration steps including a virus reduction filter. The materialwas then concentrated and formulated with 20 mM sodium phosphate and 240mM sucrose, with a resulting pH of 6.0. The composition is filteredbefore filling into glass vials at a concentration of 10 mg/mL. Eachglass vial contained 5 mL of TRU-015 (50 mg/vial).

Example 6 Combinations of TRU-016 with TRU-015 or RituxanSynergistically Increase Apoptosis in B cells

Experiments examining the effect of B cell targeted SMIPS on B cell lineapoptosis were performed. Each SMIP was tested individually and then incombination. Samples were analyzed at both 24 and 48 hours afterinitiation of incubation reactions. Annexin/PI Analysis was performed asfollows: BJAB (courtesy of Ed Clark, University of Washington), Ramos(ATCC# CRL-1596), and Daudi cells were incubated 24 or 48 hours at 37°C. in 5% CO₂ in Iscoves (Gibco) complete media with 10% FBS at 3×10⁵cells/mL and 20 μg/mL SMIP protein. In addition, 20 μg/mL goatanti-human IgG was added to reactions in order to cross link reagents onthe cell surface. Cells were then stained with Annexin V-FITC andpropidium iodide using the BD Pharmigen Apoptosis Detection Kit I(#556547), and processed according to kit instructions. Briefly, cellswere washed twice with cold PBS and resuspended in “binding buffer” at1×10⁶ cells/mL. One hundred microliters of the cells in binding bufferwere then stained with 5 μl of Annexin V-FITC and 5 μl of propidiumiodide. The cells were gently vortexed and incubated in the dark at roomtemperature for 15 minutes. Four hundred microliters of binding bufferwas then added to each sample. They were then read and analyzed on aFACsCalibur (Becton Dickinson) instrument using Cell Quest software(Becton Dickinson).

Table 2 below shows that in the presence of crosslinking, treatment withTRU-016 had a more significant effect on apoptosis of cell lines thanTRU-015 alone, although both molecules when used alone do induce someapoptosis. The increase varies depending on the cell line.

TABLE 2 Bjab Annexin V Positive No SMIP 17.5 CD20 SMIP 27 CD37 SMIP 30.6CD19 SMIP 29.1 CD20 + CD37 SMIP 41 CD20 + CD19 SMIP 37.1 CD37 + CD19SMIP 35.3 Plus GAM Ramos AnnexinV Positive AnnexinV positive cells alone3 3.3 CD20 MAb 1.4 3.1 CD37 Mab 18.3 8.7 CD19 MAb 3.7 3.1 CD40 MAb 3.98.3 CD20 + CD37 32.3 35.7 CD20 + CD19 5 10.5 CD20 + CD40 5.7 19.4 CD19 +CD37 26.9 50 CD19 + CD40 8.2 18.4

Example 7 Combinations of TRU-016 with CD20-Specific Antibodies or SMIPsSynergistically Increase CDC

Experiments were performed to determine the CDC activity of combinationsof TRU-016 with CD20-specific antibodies or SMIPS against B cells. Theamount of reagents chosen for combination experiments was 0.5 μg/mLTRU-016 while that of TRU-015 was also 0.5 μg/ml. The concentration ofrituxan was usually 0.04-0.06 μg/mL because of its higher activity insingle reagent CDC experiments. In some experiments, the concentrationof CD20 reagent was held constant at a suboptimal concentration, whilethe concentration of TRU-016 was varied to explore the minimal levels ofCD37 directed reagent required to observe augmentation effects on CDC.

Cells were suspended in Iscoves (#12440-053, Gibco/Invitrogen, Granland,N.Y.) at 5×10E5 cells/well in 75 μl. TRU-016 (75 μl), TRU-015, rituxan,or combinations of these reagents were added to the cells at twice theconcentrations indicated. Binding reactions were allowed to proceed for45 minutes prior to centrifugation and washing in serum free Iscoves.Cells were resuspended in Iscoves with human serum (#A113, Quidel, SanDiego, Calif.) at the indicated concentrations. The cells were incubated60 minutes at 37° C. Cells were washed by centrifugation and resuspendedin 125 μl PBS with 2% FBS (#16140-071, Gibco, Invitrogen, Grand Island,N.Y.), staining media. The cells were transferred to FACS cluster tubes(#4410, CoStar, Corning, N.Y.) and 125 μl staining media with 5 μlpropidium iodide (PI, #P-16063, Molecular Probes, Eugene Oreg.) wasadded. Samples were incubated 15 minutes at room temperature in the darkprior to analysis by flow cytometry using a FACsCalibur and CellQuestsoftware (Becton Dickinson).

FIG. 6 shows that at suboptimal concentrations for killing as a singleagent, TRU-015 and rituxan exhibit high levels of CDC activity whencombined with TRU-016. TRU-016 alone fails to mediate CDC unlessaggregates are present. Depletion of C1q from the reactions results inthe elimination of all CDC activity observed.

FIG. 7 shows a combination experiment performed on DHL-4 B cells.Addition of TRU-016 to the CDC reactions results in a downward shift tothe TRU-015 killing curve, demonstrating more effective killing at eachconcentration tested even though TRU-016 exhibits little or no activityalone.

FIG. 8 shows another CDC experiment where the sample reagents were mixedat the following ratios: 0.5 μ/mL TRU-015, 0.5 μg/mL TRU-016, and 0.06μg/mL rituxan. Again, the single agents are used at suboptimalconcentrations in order to see augmentation effects in the presence ofTRU-016. For both TRU-015 and rituxan, TRU-016 enhances the level of CDCkilling when added to the assays.

FIGS. 9 and 10 show graphical representations of the data for CDC assayswhere the concentration of TRU-015 or rituxan was kept constant andTRU-016 concentration was increased. Again, CDC activity was greaterwhen TRU-016 was added to the reactions, but increasing theconcentration of TRU-016 to 2.5 μg/mL from 0.5 μg/mL did notsignificantly increase the CDC-mediated killing in these experiments.

Example 8 TRU-016 Augments the ADCC and the CDC Activity ofCD20-Specific Antibodies and SMIPs

Experiments were performed to determine if combinations of TRU-016 SMIPwith CD20-specific antibodies or SMIPs could augment ADCC and CDCactivity against B cell targets.

BJAB, Ramos, and Daudi lymphoblastoid B cells (10E7) cells were labeledwith 500 μCi/mL ⁵¹Cr sodium chromate for 2 hours at 37° C. in IMDM/10%FBS. The labeled BJAB cells were washed three times in RPMI/10% FBS andresuspended at 4×10E5 cells/mL in RPMI. Heparinized, human whole bloodwas obtained from anonymous, in-house donors and PBMC isolated byfractionation over Lymphocyte Separation Media (LSM, ICN Biomedical)gradients. Buffy coats were harvested and washed twice in RPMI/10% FBSprior to resuspension in RPMI/10% FBS at a final concentration of 3×10E6cells/ml. Cells were counted by trypan blue exclusion using ahemacytometer prior to use in subsequent assays. Reagent samples wereadded to RPMI media with 10% FBS at 4 times the final concentration andfive serial dilutions for each reagent were prepared. For combinations,the reagents were premixed and diluted prior to addition to the wells.These reagents were then added to 96 well U bottom plates at 50 μl/wellfor the indicated final concentrations. The ⁵¹Cr labeled BJAB were addedto the plates at 50 μl/well (2×10E4 cells/well). The PBMCs were then,added to the plates at 100 μl/well (3×10E5 cells/well) for a final ratioof 15:1 effectors (PBMC):target (BJAB).

Effectors and targets were added to media alone to measure backgroundkilling. The ⁵¹Cr labeled BJAB were added to media alone to measurespontaneous release of ⁵¹Cr and to media with 5% NP40 (#28324, Pierce,Rockford, Ill.) to measure maximal release of ⁵¹Cr. Reactions were setup in quadruplicate wells of a 96-well plate. SMIPs were added to wellsat a final concentration ranging from 12 ng/mL to 101 μg/mL as indicatedon the graphs. For SMIP combinations, the reagents were mixed prior toaddition to the wells. Each data series plots a different single SMIP orcombination at the titration ranges described. Reactions were allowed toproceed for 6 hours at 37° C. in 5% CO₂ prior to harvesting andcounting. Fifty μl of the supernatant from each well was thentransferred to a Luma Plate 96 (#6006633, Perkin Elmer, Boston, Mass.)and dried overnight at room temperature. CPM released was measured on aPackard TopCounNXT. Percent specific killing was calculated bysubtracting (cpm {mean of quadruplicate samples} of sample−cpmspontaneous release)/(cpm maximal release-cpm spontaneous release)×100.

Data were plotted as % specific killing versus SMIP concentration. Theeffector to target ratio is indicated on each figure, and the targetcell line was also indicated. FIGS. 11, 12, and 13 show data forexperiments on different cell lines (BJAB, Daudi, and Ramos) where thesame donor was used.

In FIGS. 14 and 15 (rituxan+TRU-016) and FIGS. 16 and 17(TRU-015+TRU-016) data is presented for experiments in which the targetcell line used was BJAB. The specific killing observed for eachcombination was greater than either single reagent alone at the sameconcentration, indicating that the CD20 and CD37 targeted SMIPs augmentthe killing mediated by the other, although the augmentation effect isnot completely additive.

Thus, TRU-016 can enhance CD20-specific SMIP or CD20-specific antibodyADCC mediated killing of B cells.

Initial experiments to explore the effects of combinations of TRU-016with CD20-directed antibodies were designed to determine the relativeamounts of each reagent to use so that CDC synergy could be detectable.Ramos cells were suspended in IMDM, and TRU-016, Rituxan, orcombinations of these reagents were added to the cells to the finalconcentrations indicated in FIG. 18. Binding reactions were allowed toproceed for 45 minutes prior to centrifugation and washing in serum freeIscoves. Cells were resuspended in Iscoves with 10% NHS. The cells wereincubated 60 minutes at 37° C. In experiments shown in FIG. 18A-C, cellswere washed by centrifugation and resuspended in staining mediacontaining 0.5 μg/mL propidium iodide (PI, #P-16063, Molecular Probes,Eugene Oreg.). Samples were incubated 15 minutes at room temperature inthe dark prior to analysis by flow cytometry using a FACsCalibur andCellQuest software (Becton Dickinson).

The more highly purified TRU-016 dimer peak is a poor mediator of CDCwhen used alone, as shown in FIG. 18A by the flat dose-response curveeven at high concentrations. Because CO20 directed reagents wereefficient inducers of CDC activity, non saturating amounts of the CD20directed reagents were desirable in combination experiments, so thatsynergy between the reagents could be detected. From these initialstudies, the usual amount of reagent chosen for combination experimentswas 0.5 μg/mL or 2 μg/mL TRU-016. The concentration of Rituxan wasusually 0.04-0.06 μg/mL because of its higher activity in single reagentCDC experiments. In some experiments, the concentration of CD20 reagentwas held constant at a suboptimal concentration, while the concentrationof TRU 016 was varied to explore the minimal levels of CD37 directedreagent required to observe augmentation effects on CDC. Thus, TRU-016alone fails to mediate CDC unless aggregates are present.

FIG. 18B shows a graph of the percentage of live cells (PI negative)observed over the titration range indicated (0.06-0.5 μg/ml) whenRituxan is used alone or in combination with TRU-016 at 2.51 μg/ml.Rituxan, when used at a range of suboptimal doses for killing as asingle agent, exhibits higher levels of CDC activity at eachconcentration when combined with TRU-016 (FIG. 18B). Depletion of C1qfrom the reactions results in the elimination of all CDC activityobserved (FIG. 3B).

In FIG. 18C, samples were also incubated with FITC anti-C1q for 45minutes on ice prior to analysis by flow cytometry. Lymphocyte gatingwas on compromised cells. The percentage of cells in this gate increasedwith increasing Rituxan concentration, and the relative MFI for thispopulation of cells was graphed. FIG. 18C shows the results of a CDCexperiment where the sample reagents were mixed at the following ratios:0.5 μg/mL for TRU-016, and Rituxan concentrations ranging from 0.06μg/mL to 0.5 μg/mL, and cells stained with PI prior to flow cytometry.The results show a dose dependent increase in MFI with increasing dosesof Rituxan. The addition of TRU-016 dimer forms resulted in anadditional increase in the MFI at each concentration of Rituxan. Asimilar series of CDC assays were performed, keeping the concentrationof Rituxan constant and increasing the TRU-016 concentration. Again, CDCactivity was greater when TRU-016 was added to the Rituxan reactions,but increasing the concentration of TRU-016 to 2.5 μg/mL from 0.5 μg/mLdid not significantly increase the CDC mediated killing in theseexperiments (data not shown).

Rituxan and TRU-016 proteins used alone and in combination with oneanother were compared for their ADCC activity in vitro using a similarconcentration range as that used for the CDC assays. FIG. 18D shows theresults of an ADCC assay with labeled Ramos cell targets and human PBMCeffector cells at an effector to target ratio of 25:1, using TRU-016 orRituxan, alone and in combination with one another over theconcentration ranges indicated. Similar data were obtained at aneffector:target ratio of 12.5:1. Both the TRU-016 dimer form and Rituxanmediate significant levels of ADCC against Ramos cells expressing theCD20 and CD37 target antigens; however, the combination of the tworeagents does not result in significant augmentation in the level ofkilling.

Example 9 TRU-016 Induces Apoptosis in B cells

Experiments examining the effect of TRU-016 on B cell line apoptosiswere performed. Initial assays of the effects on apoptosis of TRU-016molecules targeted to different B cell receptors were performed usingprotein A purified material that still contained higher orderaggregates. After 24 hour treatment with CD37 antibodies or engineeredTRU-016 molecules, similar patterns of increased apoptosis were observedin multiple experiments using annexin V positive cell percentages as ameasure of apoptotic activity and both Ramos and BJAB cells as bindingtargets (data not shown).

FIG. 19A demonstrate that apoptosis is significantly increased afterincubation of B cell lines with unfractionated TRU-016. FIG. 19A shows adot plot of Annexin V-PI staining of Ramos cells after incubation for 24hours with the TRU-016 (10 μg/mL). The % of annexin V-PI double positivecells increased from 11.3% of the total population to 32.8%, and the %of annexin V positive-PI negative cells increased from 8.5% to 19.7%,indicating that apoptosis is induced after exposure to TRU-016. Similardata were obtained whether Ramos or BJAB cells were used as the bindingtargets in these assays.

Further experiments examining the effect of TRU-016 on B cell lineapoptosis were performed using the more highly purified dimer form ofTRU-016 (FIG. 19B). Samples were analyzed at both 24 and 48 hours afterinitiation of incubation reactions. Annexin/PI analysis was performed onseveral cell types using 20 μg/mL TRU-016 protein. Because apoptosis wasreduced using the dimer form of TRU-016, 20 μg/mL goat anti-human IgGwas added to reactions in order to cross link reagents on the cellsurface. Cells were then stained with Annexin V-FITC and propidiumiodide. The data shown in FIG. 19B demonstrates that the TRU-016 dimerpeak induces apoptosis of Daudi cells after 24-48 hours, but that thepresence of a crosslinking agent such as anti-human IgG results in asignificant increase in the level of CD37 targeted apoptosis.

Experiments were also performed to determine the effect of TRU-016 onnormal human B cells in culture using human PBMCs. FIGS. 20A and 20Bshows results from one such experiment, with columnar graphs of thepercentage of CD19 or CD40 positive lymphocytes (B cells) present inPBMC cultures treated for 48-72 hours with media alone, TRU-016, orRituxan.

Human PBMCs were isolated from whole blood by LSM densitycentrifugation. Cells were incubated for 48 or 72 hours with 1 μg/mL ofRituxan or TRU-016. A portion of the incubation reaction was harvestedat 48 hours and again at 72 hours after initiation of the experiment.PBMCs were washed and incubated with FITC anti-CD19, FITC anti-CD40, orFITC anti-CD3 for 45 minutes on ice. The percentage of total lymphocytesstaining with these reagents was then tabulated and compared to PBMCsamples incubated under similar conditions but without test reagents,and stained as for the treated samples. FIGS. 20A and B show columnargraphs of the fraction of the total lymphocyte population (%) which givea positive FACs signal after 48 and 72 hours with the indicatedreagents. FIG. 20C shows a composite graph from a similar experiment,showing the percent reduction from the original number of lymphocytesexpressing the indicated CD antigen (i.e. CD19, CD40 or CD3 positive)after incubation of PBMCs with TRU-016 (at 1 μg/ml) for 24 and 72 hours.

In the presence of crosslinking, treatment with the TRU-016 dimer formor Rituxan resulted in a reduction in the percentage of B lymphocytes inPBMC cultures as measured by positive staining for CD19 and CD40.Although the percentage of B lymphocytes in culture was low at theoutset of the experiment, coculture with Rituxan or TRU-016 decreasedthe number of CD19 and CD40 positive lymphocytes in the PBMC culture byapproximately 1.5-2 fold after 48 hours, and by more than 3 fold after72 hours. This general pattern of B cell depletion after 48-72 hours wasreproducible in all normal PBMC cultures tested, regardless of theinitial starting percentage of B lymphocytes in these cultures, whichranged from approximately 3% to as much as 7% of the total lymphocytes,depending on the sample.

FIG. 20C shows a columnar graph of the percentage depletion of Blymphocytes compared to T lymphocytes in short term PBMC culturesincubated with TRU-016 for 24 to 72 hours. These data indicate that theTRU-016 is capable of specific depletion of CD37 positive B lymphocytesfrom normal peripheral blood cultures, and that the low level of bindingby TRU-016 to non-B lymphocytes (FIG. 1C) is insufficient to mediatesignificant depletion of these lymphocytes from the cell population.

Example 10 Combinations of TRU-016 and Rituximab Synergistically ReduceTumor Volume in a Murine Tumor Xenograft Model

Mouse tumor xenograft studies exploring combination therapies wereperformed using nude mice (Harlan) and Ramos or Daudi human tumor lines.Ramos or Daudi tumor cells were grown in T150 flasks in IMDM/10% FBSuntil they reached 80% confluency. Five million (5×10⁶) cells were usedas a tumor inoculum per mouse. Cells were injected subcutaneously in theright flank using PBS in a total volume of 0.1 mL or 5.0×10⁷ mL. Nudemice were allowed to develop tumors and sorted into groups based ontumor size/volume. For each treatment group, 12 mice with a mean tumorvolume of approximately 222 mm³ (range=152-296 mm³) were used. Some meantumor volumes ranging from 237-251 mm³ were also used. Animals wereinjected intravenously (IV) at days 0, 2, 4, 6, and 8 with one of thefollowing reagents: TRU-016 GPC POI (peak of interest), 200 μg/mouse;rituxan, 200 μg/mouse, or human IgG (control) at 200 or 400 μg/mouse assingle reagents, or as the following combinations of reagents:Rituxan+TRU-016 at 100 μg each per mouse; or Rituxan+TRU-016 at 200 μgeach per mouse. Tumor volume was measured daily with calipers untilcompletion of the experiment (sacrifice or regression). Tumor volume asa function of treatment time was plotted for each animal and resultswere also averaged within each group.

Similar studies were also performed using smaller tumors, with micesorted into groups with smaller mean tumor volume ranging between153-158 mm³, and with larger tumors but using Daudi cells rather thanRamos cells. These studies were performed in an AAALAC accredited animalfacility and animal use program in accordance with guidelines from anInstitutional Animal Care and Use Committee (IACUC).

FIG. 21 graphs the efficacy of TRU-016 compared to huIgG, rituxan, andthe combinations at 100 μg and 200 μg each averaged over each group of12 animals. Tumor volume was plotted as a function of time aftertreatment with the IV injection(s). The average tumor volume aftertreatment with TRU-016 was smaller than that observed using the negativecontrol (huIgG). When % survival or % tumor free animals were graphed,the higher dose combination therapy exhibited higher anti-tumor activityin this in vivo tumor model. However, at the lower dose (100 μg each),the combination therapy was not as effective as each single reagent at ahigher dose.

These data indicate that TRU-016 therapy, when used in combination withrituxan at the appropriate doses, will have greater efficacy in treatingpatient tumors than rituxan therapy alone.

Example 11 TRU-016 Reduces Tumor Volume and Increases Survival in aMurine Tumor Xenograft Model

Mouse tumor xenograft studies were performed using nude mice (Harlan)and Ramos or Daudi human tumor lines. Three different studies wereperformed based on tumor type and tumor size at the time of treatmentwith the TRU-016 or other test reagent. Ramos or Daudi tumor cells weregrown and (5×10⁶) cells were injected subcutaneously in the right flankto inoculate each treated mouse with the tumor. Nude mice were allowedto develop tumors and sorted into groups based on tumor size/volume. Inthe first study, for each treatment group, 12 mice with a mean tumorvolume of 155-237 mm³ were used. Animals were injected intravenously(IV) at days 0, 2, 4, 6, and 8 with one of the following reagents:Rituximab, 200 μg/mouse; TRU-016 GPC dimer peak, 200 μg/mouse; or humanIgG (control), 400 μg/mouse. Tumor volume was measured daily withcalipers until completion of the experiment (sacrifice or regression).Tumor volume as a function of treatment time was plotted for each animaland results were also averaged within each group. Group averages wereshown in FIG. 22A, while FIG. 22B shows a comparison of the percentsurvival data for each group of mice as a function of time.

FIG. 22A shows the efficacy of TRU-016 compared to huIgG and Rituxan inthe Ramos tumor model, averaged over each group of 12 animals. Tumorvolume was plotted as a function of time after treatment with the IVinjection(s). The average tumor volume after treatment with the TRU-016was smaller than that observed using the negative control (huIgG). FIG.22B graphs the survival curves for the different treatment groups,comparing huIgG, Rituxan, and TRU-016. Administration of TRU-016,utilizing the more demanding Ramos tumor model with increased baselinetumor volume, resulted in an inhibition of tumor growth rate relative tohuman IgG (data not shown). Administration of TRU-016 to mice with thesmaller Ramos tumors resulted in both an inhibition of tumor growth andincreased median survival times.

Example 12 TRU-016 Does Not Affect the CDC Activity of Other B CellSurface Receptors

To determine whether the TRU-016 molecule augments the level of CDCactivity resulting from treatment with antibodies to other B cellsurface receptors, in addition to CD20, such as MHCII, CD19, CD80/86,and CD40, a panel of experiments was performed similar to those justdescribed for CD20-CD37 directed combinations.

Ramos cells were added to wells in Iscoves complete media with 10% FBS.The MAbs (reagent B: HD37-anti CD19, reagent C, 9.4-anti-CD45), fusionprotein (reagent D: CTLA-4 muIg-IgG2a, Ancell #501-820), and ascitesfluid (reagent A: HB10a-anti-MHC11), were added at the indicateddilutions (see FIG. 23) and duplicate reactions were set up with andwithout Rituximab (at 0.05 μg/ml) or TRU-016 (at 2 μg/ml) added.Reactions were incubated for 30 minutes at 37° C. The cells were washedand NHS was added to a final concentration of 10% in serum free media.Cells were incubated for 90 minutes at 37° C. with the complementsource. The cells were washed; propidium iodide was added to a finalconcentration of 0.5 μg/mL in PBS; the cells were incubated in the darkat room temperature for 15 minutes; and then cells were assayed by flowcytometry. Each graph in panels A-D of FIG. 23 plots the % PI positivecells over the titration ranges indicated.

In general, the data indicate that there was not a significantdifference in the level of CDC activity when antibodies directed tothese receptors were used alone or in combination with the TRU-016 (FIG.23A-D). There may be a slight increase in CDC levels for the CD19 andCD45 directed reagents when used with TRU-016 at suboptimalconcentrations. However, the differences in CDC levels are not nearly assignificant as those observed for the CD20-CD37 combination. In additionto the augmentation of CDC when CD20 and CD37 directed reagents are usedin combination, there appears to be augmentation in the level of killingobserved using combinations of anti-classII (HB10a), anti-CD19,anti-CD45 (9.4) or CTLA4Ig with Rituxan at the suboptimal dose.

Example 13 TRU-016 does not Augment the CDC Activity of Other TargetedReceptors, Including MHCII, CD19, CD80186, and CD40

To determine whether the TRU-016 molecule augments the level of CDCactivity resulting from treatment with antibodies to other B cellsurface receptors, in addition to CD20, a panel of experiments wasperformed similar to those described for CD20-CD37 directed combinations(see Example 8). The results of these experiments are shown in FIG. 23.In general, there was not a significant difference in the level of CDCactivity when antibodies directed to these receptors were used alone orin combination with the TRU-016. CDC levels slightly increased inresponse to CD19 and CD45 directed reagents when used with TRU-016 atsuboptimal concentrations. However, the differences in CDC levels werenot nearly as significant as those observed for the CD20-CD37combination (see Example 8). In addition to the augmentation of CDC whenCD20 and CD37 directed reagents are used in combination, there appearedto be augmentation in the level of killing observed using combinationsof anti-MHCII (HB10a), anti-CD19, anti-CD45 (9.4) or CTLA4Ig withRituxan at the suboptimal dose.

Example 14 TRU-016 Increases Survival in a Murine Tumor Xenograft Model

Mouse tumor xenograft studies beyond those described in Example 11 wereperformed to examine the efficacy of TRU-016 in increasing long-termsurvival using nude mice (Harlan) and either Ramos or Daudi human tumorcell lines.

Ramos and Daudi tumor cells were separately grown and (5×10⁶) cells wereinjected subcutaneously in the right flank of mice to initiate theformation of mouse tumor xenografts. After tumor development, mice weresorted into groups based on tumor size/volume (day 0). Animals wereinjected intravenously (IV) at days 0, 2, 4, 6, and 8 with one of thefollowing reagents: rituximab, 200 μg/mouse; TRU-016, 200 μg/mouse;rituximab+TRU-016 at 100 or 200 μg/mouse; or human IgG (control), 400μg/mouse. Tumor volume was blindly measured three times weekly withcalipers until completion of the experiment (sacrifice or regression).Tumor volume as a function of treatment time was plotted for each animaland results were averaged within each group. FIG. 24 shows the percentsurvival of mice with Ramos tumors (up to 90 days) after treatment withTRU-016, rituximab, or a combination thereof. The combination treatmentwith TRU-016+rituximab significantly increased median survival timeversus treatment with single agent therapy alone. FIGS. 25 and 26 showthe percent survival of mice with Daudi tumors (up to 90 days) aftertreatment with TRU-016 or rituximab. Treatment with TRU-016 increasedmedian survival time in established Daudi tumors (FIG. 25). TRU-016 wasmore effective than rituximab in maintaining survival in mice with Dauditumors (FIG. 26).

Administration of TRU-016 as a single agent in mice with establishedRamos tumors demonstrated an inhibition of tumor growth and improvedsurvival times equivalent to rituximab administered as a single agent,and was superior to HuIgG control-treated mice. Pooled data from 3experiments demonstrated that TRU-016 and rituximab combination therapyresulted in a statistically significantly improvement in survival timecompared to TRU-016 (p=0.028) or rituximab (p=0.045) monotherapies.Complete tumor regressions were also enhanced for the TRU-016 andrituximab combination groups. Forty-two percent of the TRU-016+rituximab200 μg combination group were able to achieve long-term completeregression of their tumors compared to a 20% tumor regression rate inmice treated with either TRU-016 or rituximab alone (see Table 3 andFIG. 24).

TABLE 3 Survival after Treatment in Established Ramos Tumors Percentageof Tumor-Free Median Survival Mice at Day 90 Time (Days) TRU-016 +rituximab 42 31 (200 μg) TRU-016 + rituximab 25 24 (100 μg) TRU-016 (200μg) 20 16 Rituximab (200 μg) 20 17 HuIgG 0 10

Reduction in tumor growth and improved survival time were found afterTRU-016 treatment in the Daudi tumor xenograft model (see Table 4 andFIGS. 25 and 26). TRU-016 administration significantly enhanced survivaltime compared to the control group. An increase in percentage oftumor-free mice was also observed with SMIP-016 treatment in this modelcompared to both control and rituximab groups.

TABLE 4 Survival, after Treatment in Established Daudi Tumors Percentageof Tumor Free Median Survival Mice at Day 90 Time (Days) TRU-016 (100μg) 25 24 Rituximab (100 μg) 0 17 HuIgG 0 15

Treatment with a CD37-directed SMIP (TRU-016) is as effective asrituximab monotherapy in reducing tumor volume and increasing survivaltime in the Ramos tumor xenograft model. TRU-016+rituximab combinationtherapy demonstrated enhanced benefit in reducing tumor volume andsignificantly improving survival time compared to either rituximab orTRU-016 monotherapy in the Ramos tumor xenograft model. In the Daudixenograft model, TRU-016-treated mice demonstrated a statisticallysignificant increase in median survival time compared to HuIgG controls.Treatment with rituximab did not extend survival times compared tocontrol mice. These data highlight the efficacy of a CD37-directedtherapy in these NHL xenograft models.

Example 15 TRU-016 Potentiates Fludarabine-Induced Cell Death in CLLCells In Vitro

Fludarabine is a chemotherapy drug used in the treatment ofhematological malignancies. Fludarabine is a purine analog that inhibitsDNA synthesis by interfering with ribonucleotide reductase and DNApolymerase. Fludarabine is active against both dividing and restingcells. Fludarabine is highly effective in the treatment of chroniclymphocytic leukemia (CLL), producing higher response rates thanalkylating agents such as chlorambucil alone (Rai et al., N. Engl. J.Med. 343:1750-1757, 2000). Fludarabine is used in various combinationswith cyclophosphamide, mitoxantrone, dexamethasone and rituximab in thetreatment of indolent lymphoma and non-Hodgkins lymphoma. However,resistance to fludarabine has also been observed in treatment.Fludarabine induces caspase-dependent apoptosis in CLL cells, andapoptosis mediated by TRU-016 appears to be independent of caspaseactivation. The present study examined the effect of TRU-016 withfludarabine on CLL cells.

Cells were treated with TRU-016 at dosages ranging from 0.1-100 μg/mLand with fludarabine at dosages ranging from 0-20 μM (see FIG. 27).TRU-016 was provided by Trubion Pharmaceuticals (Seattle, Wash.).Fludarabine (F-araA) was purchased from SIGMA (St. Louis, Mo.). RPMI1640 media was purchased from Invitrogen (Carlsbad, Calif.). Fluoresceinisothiocyanate (FITC)-labeled annexin V, and propidium iodide (P1) werepurchased from BD Pharmingen, San Diego, Calif.13-(4,5-dimethylthiazol-2-y1)-2,5-diphenyltetrazolium bromide (MTT) waspurchased from Sigma (St. Louis, Mo.). B-CLL cells were isolatedimmediately following donation using ficoll density gradientcentrifugation (Ficoll-Paque Plus, Amersham Biosciences, Piscataway,N.J.). Isolated mononuclear cells were incubated in RPM′ 1640 mediasupplemented with 10% heat-inactivated fetal bovine serum (FBS, HycloneLaboratories, Logan, Utah), 2 mM L-glutamine (Invitrogen, Carlsbad,Calif.), and penicillin (100 U/mL)/streptomycin (100 μg/ml;Sigma-Aldrich, St. Louis) at 37° C. in an atmosphere of 5% CO2. Freshlyisolated B-CLL cells were used for all the experiments described hereinexcept for the surface staining. For those samples with less than 90% Bcells, negative selection was applied to deplete non-B cells using Bcell Isolation Kit 11 (Miltenyi Biotec, Auburn, Calif.) or by“Rosette-Sep” kit from Stem Cell Technologies (Vancouver, BritishColumbia, Canada) according to the manufacture suggested protocol. Raji(Human Burkitt's lymphoma cell line) cell line was purchased from ATCCand maintained in RPM′ 1640 media containing 10% FBS, supplemented withpenicillin, streptomycin and glutamine. Cells were split 1:3 when thecell density reached 1×106/mL. Media was changed the night before eachstudy to assure fresh cells being used.

Cells were treated in vitro as described herein. 1:4 serial dilution offludarabine (44, 11, 2.8, 0.7, 0.17 and 0.04 μM) was prepared in a6-well plate by transferring 2 mL of drug-containing media to the nextwell containing 6 mL blank media. In a separate 6-well plate, 1:4 serialdilution of TRU-016 (44, 11, 2.8, 0.7, 0.17, and 0.04 μg/ml) in mediawas prepared using the same dilution method. From each of the plates,0.45 mL media was transferred to a designed well in a 48-well plate tomake a mixed drug solution in media (0.9 mL total in each well).Suspended CLL cells in media at a density of 1×107 cells/mL (0.1 mL)were then added to the 0.9 mL media in each well to make a final densityof 1×106 cells/mL. For Raji cells, the final cell density was 5×104cells/mL. Thus, the cell suspension used was 5×105 cells/mL. For the MTTassays, drug serial dilutions were prepared in 96-well plates, andtransferred to other 96-well plates for incubation with cells. The totalvolume for incubation is 200 μL (90 pL of fludarabine solution, 90 pL ofTRU-016 solution, and 20 μL cell suspension). Cell viability wasassessed using MTT assays at 48 hr, and apoptosis was measured usingAnnexin V/PI at 24 hr.

MTT assays were performed to measure cell viability as described herein.Briefly, 106 CLL cells were seeded to 96-well plates. Cells wereincubated for 48 hours. 50 p1 of MTT working solution (2 mg/ml, preparedfrom 5 mg/mL MTT reagent mixed with RPMI 1640 2:3 v/v) was added to eachwell, and the cells were incubated for 8 hours. Plates were centrifugedand supernatant was removed and dissolved in 100 pl lysis solution.Samples were measured with a plate reader at 0.D.540. Cell viability wasexpressed as the percentage of viability compared with media control.

The apoptosis of CLL cells after incubation with antibodies was measuredusing annexin V-FITC/propidium iodide (P1) staining with FACS analysis.5×105 cells in 200 p1 l× binding buffer (BD Pharmingen) were stainedwith 5 pL annexin V (BD Pharmingen) and 5 pL PI (BD Pharmingen), andkept in the dark at room temperature for 15 minutes before suspensionwith 300 p1 l× buffer and analyzed by flow cytometry. Cells withoutstaining, cells stained only with Annexin V, and cells stained only withPI were prepared. For all flow cytometry experiments, FACS analysis wasperformed using a Beckman-Coulter EPICS XL cytometer (Beckman-Coulter,Miami, Fla.). Fluorophores were excited at 488 nm. FITC-fluorescence wasmeasured with FL1, while PI and PE fluorescence was measured with FL3.System II software package (Beckman-Coulter) was applied to analyze thedata. The counted cell number was set at 10,000 for each sample.

A synergistic effect was determined by use of the isobologram method. Toidentify synergy, the effect of a drug combination was compared to theeffect of each drug alone. This is based on the equation:Ca/Ca,b+Cb/Cb,a ═Cl, where Ca and Cb are the concentration of drug A anddrug B alone, respectively, to produce a desired effect (e.g. 50% celldeath). Ca,b and Cb,a are the concentrations of drug A and drug B in acombination, respectively, to produce the same effect. Cl is thecombination index. The concentrations of fludarabine and TRU-016, whichelicit 50% death (1050) were determined and are shown in FIG. 27C [1050of Fludarabine (I) and IC50 of TRU-016 (11)1 The straight line betweenthese two points on the axes is the line of additive effect.Subsequently, different combinations of fludarabine and TRU-016 thatachieve 50% cell death were also determined from the viability study andplotted to the same graph. When points fall below the additivity line,synergy is indicated. When points rise above the line, antagonism isindicated. When points are on the line, additivity is indicated.

FIG. 27 shows that TRU-016 effectively reduced relative cell viabilityin cells treated with fludarabine, thereby potentiating the cytotoxiceffect of fludarabine alone. Thus, this study provides evidence thatTRU-016 can be co-administered with fludarabine, resulting in increasedeffectiveness (i.e., synergistic reduction of CLL cells) in thetreatment of hematological malignancies.

Example 16 TRU-016 Induces Direct Cytotoxicity in Rituximab-ResistantCells

As disclosed herein, rituximab is a monoclonal antibody used in thetreatment of NHL, FCC, MCL, DLCL, SLL, and CLL. The present study wasundertaken to determine the efficacy of TRU-016 in inducing directcytotoxicty in cells resistant to rituximab.

Rituximab-resistant cells (1×106 cells) (Raji 4RH and RL 4RH, suppliedby Dr. Myron S. Czuczman, Roswell Park Cancer Institute, Buffalo, N.Y.)were treated with herceptin (10 μg/mL), rituximab (10 μg/mL), or TRU-016(5 μg/mL) in the presence of a five-fold excess of goat anti-human IgGfor 24 hours. Direct cytoxicity was measured by annexin/PI staining andcell viability (percent) was calculated relative to control cells (cellstreated with herceptin).

TRU-016 induced greater cell toxicity than rituximab inrituximab-resistant cell lines (see FIG. 28). Thus, TRU-016 is aneffective agent for inducing cytoxicity in rituximab-resistant cells,making it useful as a therapeutic in diseases characterized by orinvolving rituximab-resistant cells, such as some B cells.

Example 17 TRU-016 Induces Tyrosine Phosphorylation in CD19+Primary CLLB Cells

To determine how TRU-016 induces signal transduction in B cells,experiments were performed to examine the effect of TRU-016 on tyrosinephosphorylation.

Freshly isolated CD19+ cells (−50-100×106) from CLL patients weresuspended at a concentration of 5×106/m1 PBS. Cells were then incubatedfor 10 minutes at 37° C., 5% CO2, with control, trastuzumab (herceptin),or TRU-016 at a final concentration of 5 ug/ml. Cells were spun down,supernatant was removed, and cells were resuspended in fresh PBS ofinitial volume. Goat anti-human Fc fragment specific crosslinker (25ug/ml) was added and cells were incubated for an additional 5 minutes.Cells were again spun down, supernatant was removed, and cells werelysed in 1 ml of RIPA lysis buffer with protease and phosphataseinhibitors (10 mM Tris, ph7.4, 150 mM NaCl, 1% Triton X-100, 1%deoxycholic acid, 0.1% SDS and 5 mM EDTA all final concentrations. Sigmaprotease inhibitor cocktail cat #P-8340; Sigma phosphatase inhibitorcocktail: serine/threonine phosphatase inhibitor cocktail cat #P-2850;and tyrosine phosphatase inhibitor cat #P-5726; PMSF (100 mM) were allused. The inhibitors were added to the lysis buffer immediately prior touse at a 1:100 dilution. Protein concentration in the lysates wasquantified by the bicin choninic acid (BCA) method (Pierce, Rockford,Ill.). The control arid treated protein samples (500 ug total protein)were separated by two-dimensional gel electrophoresis (pH Range 3-10)(1st Dimension) and 10% SDS-PAGE (2nd Dimension). The protein wastransferred to 0.2 Nm nitrocellulose membranes (Schleicher & Schuell,Keene, N.H.) and subjected to immunoblot analysis usinganti-phosphotyrosine antibody clone 4G10 (Upstate Biotechnology), usingstandard protocol. Horseradish peroxidase (HRP)-conjugated goatanti-rabbit IgG was used as a secondary antibody. Detection of thephosphoprotein was made with chemiluminescent substrate (SuperSignal,Pierce Inc. Rockford, Ill.).

TRU-016 induced tyrosine phosphorylation in CD19+ primary CLL B cells,as shown by two-dimensional gel analysis (see FIG. 29). Thus, theseexperiments show that one way that TRU-016 acts is via a tyrosinephosphorylation pathway.

Example 18 Humanized TRU-016 Molecules

As set out in Example 1, CD37-specific SMIPs (such as TRU-016) aredescribed in co-owned U.S. application Ser. No. 10/627,556 and U.S.Patent Application Publication Nos. 2003/133939, 2003/0118592 and2005/0136049. Those descriptions are incorporated by reference herein.An exemplary CD37-specific SMIP, TRU-016 polypeptide (SEQ ID NO: 2), wasproduced and described therein. The present example provides humanizedTRU-016 SMIPs.

Humanized antibodies are known in the art and are discussed in UnitedStates Patent Application Publication No. 2006/0153837. The presentapplication uses the techniques involved in antibody humanization(discussed below) to humanize SMIPs, and particularly to humanizeTRU-016.

“Humanization” is expected to result in an antibody that is lessimmunogenic, with complete retention of the antigen-binding propertiesof the original molecule. In order to retain all of the antigen-bindingproperties of the original antibody, the structure of its antigenbinding site should be reproduced in the “humanized” version. This canbe achieved by grafting only the nonhuman CDRs onto human variableframework domains and constant regions, with or without retention ofcritical framework residues (Jones et al, Nature 321:522 (1986);Verhoeyen et al, Science 239:1539 (1988)) or by recombining the entirenonhuman variable domains (to preserve ligand-binding properties), but“cloaking” them with a human-like surface through judicious replacementof exposed residues (to reduce antigenicity) (Padlan, Molec. Immunol.28:489 (1991)).

Essentially, humanization by CDR grafting involves recombining only theCDRs of a non-human antibody onto a human variable region framework anda human constant region. Theoretically, this should substantially reduceor eliminate immunogenicity (except if allotypic or idiotypicdifferences exist). However, it has been reported that some frameworkresidues of the original antibody also may need to be preserved(Reichmann et al, Nature, 332:323 (1988); Queen et al, Proc. Natl. Acad.Sci. USA, 86:10,029 (1989)).

The framework residues that need to be preserved are amenable toidentification through computer modeling. Alternatively, criticalframework residues may potentially be identified by comparing knownantigen-binding site structures (Padlan, Malec. Immun., 31(3):169-217(1994)), incorporated herein by reference.

The residues that potentially affect antigen binding fall into severalgroups. The first group comprises residues that are contiguous with theantigen site surface, which could therefore make direct contact withantigens. These residues include the amino-terminal residues and thoseadjacent to the CDRs. The second group includes residues that couldalter the structure or relative alignment of the CDRs, either bycontacting the CDRs or another peptide chain in the antibody. The thirdgroup comprises amino acids with buried side chains that could influencethe structural integrity of the variable domains. The residues in thesegroups are usually found in the same positions (Padlan, 1994, supra)although their positions as identified may differ depending on thenumbering system (see Kabat et al, “Sequences of proteins ofimmunological interest, 5th ed., Pub. No. 91-3242, U.S. Dept. Health &Human Services, NIH, Bethesda, Md., 1991).

Although the present invention is directed to the humanization of SMIPsand not antibodies, knowledge about humanized antibodies in the art isapplicable to the SMIPs according to the invention. Some examples ofhumanized TRU-016 molecules are set out in Table 5 below.

To make humanized TRU-016 constructs of the invention, the mouseframework regions of TRU-016 were aligned to human VH1 and VH5 frameworkresidues for the heavy chain and VK1 and VK3 for the light chain. Bestmatches were analyzed for framework compatibility with the CDRs of themouse variable regions. Although there were several equally compatiblecombinations to chose from, we had previous success using the VK3(C01668), VH5-51(Z12373) combination, so the humanized anti-CD37 SMIPswere designed using these human frameworks joined by a 15aa Gly4Ser((g4s)3) scFv linker. The VK3 construct was constructed with JK1 as apreferred FR4 match and the VH5 was constructed with JH2 coding for FR4,as with previously-described constructs. SMIPs were constructed de novousing overlapping oligonucleotide PCR. Full-length products were clonedinto the SMIP expression vector in frame with the human IgG1 hinge, CH2,and CH3. These clones were sequence verified, transfected into COS-7cells and 3-day conditioned media tested for binding to the 8-celllymphoma line, Ramos. In order to increase humanization, changes wereincorporated into CDR1 of the light chain at positions L25, L27 and L28and were well tolerated, showing equal binding activity with theoriginal humanized molecule 019001. Further DNA constructs were made ina similar fashion to alter the CDR3 of the VH region by incorporatinggermline amino acids, H100-H102, encoded by various human JH regions.Constructs were examined for expression level and degree of binding toCD37 on Ramos cells.

TABLE 5 Humanized TRU-016 Constructs DNA SEQ AA Construct ID SEQ No.Description Linker Hinge NO: ID NO: 019001 Vk3:VH5-51 15aa SSC-P 5 6gly4ser 019002 Vk3:VH5-51 Linker 15aa SSC-P 7 8 (TG-SS) gly4ser 019003Vk3:VH5-51 VH V11S 15aa SSC-P 9 10 gly4ser 019004 Vk3:VH5-51 VK3, cdr115aa SSC-P 11 12 (E →Q) gly4ser 019005 Vk3:VH5-51 VK3, cdr1 15aa SSC-P13 14 (N →S) gly4ser 019006 Vk3:VH5-51 VK3, cdr1 15aa SSC-P 15 16 (T →A) gly4ser 019010 mVk:VH5-5a 15aa SSC-P 17 18 gly4ser 019011 Vk3:mVH(linker G-S 15aa SSC-P 19 20 mutation) gly4ser 019017 Vk3:VH5 VH3 FW115aa SSC-P 21 22 gly4ser 019018 mVH:Vk3 15aa SSC-P 23 24 gly4ser 019019Vk3:mVH (019011 with 15aa SSC-P 25 26 2H7 Leader) gly4ser 019021 mVH:Vk315aa SSC-P 27 28 gly4ser 019023 Vk3:mVH (fixed 019011 15aa SSC-P 29 30GS4 mutation) gly4ser 019024 Vk3:mVH (fixed 019011 15aa SSC-P 31 32 GS4mutation) gly4ser 019025 Vk3:VH5 VH3 FW1 15aa SSC-P 33 34 gly4ser 019026Vk3:VH5 VH3 FW1 15aa SSC-P 35 36 gly4ser 019032 Vk3:VH5 VH3-13 FW1 15aaSSC-P 37 38 gly4ser 019033 Vk3:VH5 VH3-13 FW1 15aa SSC-P 39 40 gly4ser019034 Vk3:VH5 VH3-13 L11S 15aa SSC-P 41 42 FW1 gly4ser 019035 Vk3:VH5VH3-13 L11S 15aa SSC-P 43 44 FW1 gly4ser 019037 Vk3(CDR-L1 15aa SSC-P 4546 changes):VH5 gly4ser 019041 019006-CDR-H3 JH4 15aa SSC-P 47 48gly4ser 019043 019006-CDR-H3 JH6 15aa SSC-P 49 50 gly4ser 019044019006-CDR-H3 JH5a 15aa SSC-P 51 52 gly4ser 019045 019006-CDR-H3 JH5b15aa SSC-P 53 54 gly4ser 019046 019006-CDR-H3 JH1 15aa SSC-P 55 56gly4ser 019047 019006-CDR-H3 JH3a 15aa SSC-P 57 58 gly4ser 019048019006-CDR-H3 JH3b 15aa SSC-P 59 60 gly4ser 019049 019006-CDR-H3 JH215aa SSC-P 79 80 gly4ser 019050 019006-CDR-H2 15aa SSC-P 81 82 changesgly4ser 019051 019044 20aa CPPCP 83 84 gly4ser 019008 85 86 019009 87 88

The amino acid consensus sequence of humanized TRU-016 construct no.019001 (SEQ ID NO: 6; H016-019001) and non-humanized TRU-016 (SEQ ID NO:2; 016-G28-1) is shown with Kabat numbering in FIG. 30A. FIG. 30 B showsthe amino acid sequence alignments of humanized TRU-016 construct nos.019001 (SEQ ID NO: 6), 019008 (SEQ ID NO: 86), and 019009 (SEQ ID NO:88).

DNA and amino acid sequence alignments of three humanized constructs ofTRU-016 (019001, 019041, and 019044), demonstrating high CD37-specificbinding to Ramos B cells are shown in FIG. 31.

FASTA formatted DNA and amino acid sequence alignments of the same threehumanized constructs of TRU-016 (019001, 019041, and 019044) are shownin FIG. 32.

Additional hinge regions (Table 6) and framework regions (Table 7) thatmay be used in the humanized TRU-016 molecules of the invention areprovided below.

TABLE 6 Hinge Regions for Humanized TRU-016 SMIPs Hinge SEQ IDdescription DNA or Amino Acid Sequence NO: ccc(p)-gagcccaaatcttgtgacaaaactcacacatgtccaccgtgccca 89 hlgG1 (DNA) ccc(p)-EPKSCDKTHTCPPCP 90 hlgG1 (AA scc(p)-gagcccaaatcttctgacaaaactcacacatgtccaccgtgccca 91 hlgG1 (DNA) scc(p)-EPKSSDKTHTCPPCP 92 hlgG1 (AA) scc(s)-gagcccaaatcttctgacaaaactcacacatgtccaccgtgctca hlgG1 (DNA) scc(s)-EPKSSDKTHTCPPCS 94 hlgG1 (AA) scs(s)-gagcccaaatcttgtgacaaaactcacacatgtccaccgagctca 95 hlgG1 (DNA) scs(s)-EPKSSDKTHTCPPSS 96 hlgG1 (AA) sss(p)-gagcccaaatcttctgacaaaactcacacatctccaccgagccca 97 hlgG1 (DNA) sss(p)-EPKSSDKTHTSPPSP 98 hlgG1 (AA) sss(s)-gagcccaaatcttctgacaaaactcacacatctccaccgagctca 99 hlgG1 (DNA) sss(s)-EPKSSDKTHTSPPSS 100 hlgG1 (AA) csc(p)-gagcccaaatcttgtgacaaaactcacacatctccaccgtgccca 101 hlgG1 (DNA) csc(p)-EPKSCDKTHTSPPCP 102 hlgG1 (AA) csc(s)-gagcccaaatcttgtgacaaaactcacacatctccaccgtgctca 103 hlgG1 (DNA) csc(s)-EPKSCDKTHTSPPCS 104 hlgG1 (AA) ssc(p)-gagcccaaatcttctgacaaaactcacacatctccaccgtgccca 105 hlgG1 (DNA) ssc(p)-EPKSSDKTHTSPPCP 106 hlgG1 (AA) scs(s)-gagcccaaatcttctgacaaaactcacacatctccaccgtgctca 107 hlgG1 (DNA) scs(s)-EPKSSDKTHTSPPCS 108 hlgG1 (AA) css(p)-gagcccaaatcttgtgacaaaactcacacatctccaccgagccca 109 hlgG1 (DNA) css(p)-EPKSCDKTHTSPPSP 110 hlgG1 (AA) css(s)-gagcccaaatcttgigacaaaactcacacatctccaccgagctca 111 hlgG1 (DNA) css(s)-EPKSCDKTHTSPPSS 112 hlgG1 (AA) scs(s)-gagcccaaatcttgtgacaaaactcacacatgtccaccgagctca 113 hlgG1 (DNA) scs(s)-EPKSSDKTHTCPPSS 114 hlgG1 (AA) hlgA1 VPSTPPTPSPSTPPTPSPS 115 hlgA2VPPPPP 116 hlgG3 gagctcaaaactcctctcggggatacgacccatacgtgtccccgc 117 (DNA)tgtcctgaaccgaagtcctgcgatacgcctccgccatgtccacggtgcccagagcccaaatcatgcgatacgcccccaccgtgtccccgctgtcctgaaccaaagtcatgcgataccccaccaccatgtccaagatgccca hlgG3 (AA)ELKTPLGDTTHTCPRCPEPKSCDTPPPCPRCP 118 EPKSCDTPPPCPRCPEPKSCDTPPPCPRCPlgG315hscc gagcccaaatcttctgacacacctcccccatgcccacggtgcccc 119 (DNA)lgG315hscc EPKSSDTPPPCPRCP 120 (AA) lgG315hcssgagcccaaatcttgtgacacacctcccccatccccacggtcccca 121 (DNA) fgG315hcssEPKSCDTPPPSPRSP 122 (AA) lgG315hsssgagcccaaatcttctgacacacctcccccatccccacggtcccca 123 (DNA) lgG315hsssEPKSSDTPPPSPRSP 124 (AA) lgG3h15cscgagcccaaatcttgtgacacacctcccccatccccacggtgccca 125 (DNA) lgG3h15cscEPKSCDTPPPSPRCP 126 (AA) hlgD ESPKAQASSVPTAQPQAEGSLAKATTAPATTR 127NTGRGGEEKKKEKEKEEQEERETKTP

TABLE 7 Framework Regions for Humanized TRU-016 SMIPs V- SEQ ID regionNO: Human VH Framework Regions for anti-CD37 Humanization FR1 VH1QVQLVQSGAEVKKPGASVKVSCKASGYTFT 140 VH1 QVQLVQSGAEVKKPGSSVKVSCKASGGTFS141 VH1 QVQLVQSGAEVKKPGSSVKVSCKASGGIFS 142 VH1EVQLVQSGAEVKKPGATVKISCKVSGYTFT 143 VH5 EVOLVQSGAEVKKPGESLKISCKGSGYSFT144 VH5 EVQLVQSGAEVKKPGESLRISCKGSGYSFT 145 VH7QVQLVQSGSELKKPGASVKVSCKASGYTFT 146 FR2 VH1 WVRQAPGQGLEWMG 147 VH1WVRQAPGQGLEWMG 148 VH1 WVRQAPGQGLEWMG 149 VH1 WVQQAPGKGLEWMG 150 VH5WVRQMPGKGLEWMG 151 VH5 WVRQMPGKGLEWMG 152 VH7 WVRQAPGQGLEWMG 153 FR3 VH1RVTMTTDTSTSTAYMELRSLRSDDTAVYYCAR 154 VH1RVTITADESTSTAYMELSSLRSEDTAVYYCAR 155 VH1RVTITADKSTSTAYMELSSLRSEDTAVYYCAR 156 VH1RVTITADTSTDTAYMELSSLRSEDTAVYYCAT 157 VH5QVTISADKSISTAYLQWSSLKASDTAMYYCAR 158 VH5HVTISADKS1STAYLQWSSLKASDTAMYYCAR 159 VH7RFVFSLDTSVSTAYLQISSLKAEDTAVYYCAR 160 FR4 WGQGTLVTVSS 161 WGRGTLVTVSS 162WGQGTMVTVSS 163 WGQGTMVTVSS 164 WGQGTLVTVSS 165 WGQGTLVTVSS 166WGQGTLVTVSS 167 WGQGTTV7VSS 168 WGKGTTVTVSS 169Human VK Framework Regions for anti-CD37 Humanization FR1 VK3EIVMTQSPATLSVSPGERATLSC 170 VK3 EIVLTQSPATLSLSPGERATLSC 171 VK1DIMITQSPSSLSASVGDRVTITC 172 VK1 DIQMTQSPSSLSASVGDRVTITC 173 VK1DIMITQSPSSLSASVGDRVTITC 174 VK1 NIQMTQSPSAMSASVGDRVTITC 175 VK1DIQMTQSPSSLSASVGDRVTITC 176 VK1 AIQLTQSPSSLSASVGDRVTITC 177 VK1DIQLTQSPSFLSASVGDRVTITC 178 VK1 AIRMTQSPFSLSASVGDRVTITC 179 VK1AIQMTQSPSSLSASVGDRVTITC 180 VK1 DIQMTQSPSTLSASVGDRVTITC 181 FR2 VK3WYQQKPGQAPRLLIY 182 VK3 WYQQKPGQAPRLLIY 183 VK1 WYQQKPGKAPKLLIY 184 VK1WYQQKPGKVPKLLIY 185 VK1 WYQQKPGKAPKRLIY 186 VK1 WFQQKPGKVPKHLIY 187 VK1WFQQKPGKAPKSLIY 188 VK1 WYQQKPGKAPKLLIY 189 VK1 WYQQKPGKAPKLLIY 190 VK1WYQQKPAKAPKLFIY 191 VK1 WYQQKPGKAPKLLIY 192 VK1 WYQQKPGKAPKLLIY 193 FR3VK3 GIPARFSGSGSGTEFTLTISSLQSEDFAVYYC 194 VK3GIPARFSGSGSGTDFTLTISSLEPEDFAVYYC 195 VK1GVPSRFSGSGSGTDFTLTISSLQPEDFATYYC 196 VK1GVPSRFSGSGSGTDFTLTISSLQPEDVATYYC 197 VK1GVPSRFSGSGSGTEFTLTISSLQPEDFATYYC 198 VK1GVPSRFSGSGSGTEFTLTISSLQPEDFATYYC 199 VK1GVPSRFSGSGSGTDFTLTISSLQPEDFATYYC 200 VK1GVPSRFSGSGSGTDFTLTISSLQPEDFATYYC 201 VK1GVPSRFSGSGSGTEFTLTISSLQPEDFATYYC 202 VK1GVPSRFSGSGSGTDYTLTISSLQPEDFATYYC 203 VK1GVPSRFSGSGSGTDFTLTISSLQPEDFATYYC 204 VK1GVPSRFSGSGSGTEFTLTISSLQPDDFATYYC 205 FR4 FGQGTKVEIK 206 FGQGTKLEIK 207FGPGTKVDIK 208 FGGGTKVEIK 209 FGQGTRLEIK 210

Numerous modifications and variations in the invention as set forth inthe above illustrative examples are expected to occur to those skilledin the art. Consequently only such limitations as appear in the appendedclaims should be placed on the invention.

DNA and Amino Acid Sequences for SEQ ID NOS: 79-88 SEQ Construct ID #NO: DNA or Amino Acid Sequence 019049 79aagcttgccgccatggaagccccagcgcagcttctcttcctcctgctactctggctcccagataccaccggagaaattgtgttgacacagtctccagccaccctgtctttgtctccaggcgaaagagccaccctctcctgccgagcaagtgaaaatgtttacagctacttagcctggtaccaacagaaacctggccaggctcctaggctcctcatctattttgcaaaaaccttagcagaaggaattccagccaggttcagtggcagtggatccgggacagacttcactctcaccatcagcagcctagagcctgaagattttgcagtttattactgtcaacatcattccgataatccgtggacattcggccaagggaccaaggtggaaatcaaaggtggcggtggctcgggcggtggtggatctggaggaggtgggaccggtgaggtgcagctggtgcagtctggagcagaggtgaaaaagcccggagagtctctgaagatttcctgtaagggatccggttactcattcactggctacaatatgaactgggtgcgccagatgcccgggaaaggcctcgagtggatgggcaatattgatccttattatggtggtactacctacaaccggaagttcaagggccaggtcactatctccgccgacaagtccatcagcaccgcctacctgcaatggagcagcctgaaggcctcggacaccgccatgtattactgtgcacgctcagtcggccctttcgacctctggggcagaggcaccctggtcactgtctcctctgatcaggagcccaaatcttctgacaaaactcacacatctccaccgtgcccagcacctgaactcctgggtggaccgtcagtcttcctcttccccccaaaacccaaggacaccctcatgatctcccggacccctgaggtcacatgcgtggtggtggacgtgagccacgaagaccctgaggtcaagttcaactggtacgtggacggcgtggaggtgcataatgccaagacaaagccgcgggaggagcagtacaacagcacgtaccgtgtggtcagcgtcctcaccgtcctgcaccaggactggctgaatggcaaggagtacaagtgcaaggtctccaacaaagccctcccagcccccatcgagaaaaccatctccaaagccaaagggcagccccgagaaccacaggtgtacaccctgcccccatcccgggatgagctgaccaagaaccaggtcagcctgacctgcctggtcaaaggcttctatccaagcgacatcgccgtggagtgggagagcaatgggcagccggagaacaactacaagaccacgcctcccgtgctggactccgacggctccttcttcctctacagcaagctcaccgtggacaagagcaggtggcagcaggggaacgtcttctcatgctccgtgatgcatgaggctctgcacaaccactacacgcagaagagcctctc cctgtctccgggtaaatgatctaga 019049 80MEAPAQLLFLLLLWLPDTTGEIVLTQSPATLSLSPGERATLSCRASENVYSYLAWYQQKPGQAPRLLIYFAKTLAEGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQHHSDNPWTFGQGTKVEIKGGGGSGGGGSGGGGTGEVQLVQSGAEVKKPGESLKISCKGSGYSFTGYNMNWVRQMPGKGLEWMGNIDPYYGGTTYNRKFKGQVTISADKSISTAYLQWSSLKASDTAMYYCARSVGPFDLWGRGTLVTVSSDQEPKSSDKTHTSPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSP GK 019050 81aagcttgccgccatggaagccccagctcagcttctcttcctcctgctactctggctcccagataccaccggagaaattgtgttgacacagtctccagccaccctgtctttgtctccaggcgaaagagccaccctctcctgccgagcaagtgaaaatgtttacagctacttagcctggtaccaacagaaacctggccaggctcctaggctcctcatctattttgcaaaaaccttagcagaaggaattccagccaggttcagtggcagtggatccgggacagacttcactctcaccatcagcagcctagagcctgaagattttgcagtttattactgtcaacatcattccgataatccgtggacattcggccaagggaccaaggtggaaatcaaaggtggcggtggctcgggcggtggtggatctggaggaggtggggctagcgaggtgcagctggtgcagtctggagcagaggtgaaaaagcccggagagtctctgaagatttcctgtaagggatccggttactcattcactagctacaatatgaactgggtgcgccagatgcccgggaaaggcctggagtggatgggcaatattgatccttattatggtggtactaactacgcccagaagttccagggccaggtcactatctccgccgacaagtccatcagcaccgcctacctgcaatggagcagcctgaaggcctcggacaccgccatgtattactgtgcacgctcagtcggccctatggactactggggccgcggcaccctggtcactgtctcctctgatcaggagcccaaatcttctgacaaaactcacacatctccaccgtgcccagcacctgaactcctgggtggaccgtcagtcttcctcttccccccaaaacccaaggacaccctcatgatctcccggacccctgaggtcacatgcgtggtggtggacgtgagccacgaagaccctgaggtcaagttcaactggtacgtggacggcgtggaggtgcataatgccaagacaaagccgcgggaggagcagtacaacagcacgtaccgtgtggtcagcgtcctcaccgtcctgcaccaggactggctgaatggcaaggagtacaagtgcaaggtctccaacaaagccctcccagcccccatcgagaaaaccatctccaaagccaaagggcagccccgagaaccacaggtgtacaccctgcccccatcccgggatgagctgaccaagaaccaggtcagcctgacctgcctggtcaaaggcttctatccaagcgacatcgccgtggagtgggagagcaatgggcagccggagaacaactacaagaccacgcctcccgtgctggactccgacggctccttcttcctctacagcaagctcaccgtggacaagagcaggtggcagcaggggaacgtcttctcatgctccgtgatgcatgaggctctgcacaaccactacacgcagaagagc ctctccctgtctccgggtaaaatga 019050 82MEAPAQLLFLLLLWLPDTTGEIVLTQSPATLSLSPGERATLSCRASENVYSYLAWYQQKPGQAPRLLIYFAKTLAEGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQHHSDNPWTFGQGTKVEIKGGGGSGGGGSGGGGTGEVQLVQSGAEVKKPGESLKISCKGSGYSFTGYNMNWVRQMPGKGLEWMGNIDPYYGGTTYNRKFKGQVTISADKSISTAYLQWSSLKASDTAMYYCARSVGPFDLWGRGTLVTVSSDQEPKSSDKTHTSPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLIVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSP GK 019051 83aagcttgccgccatggaagccccagcgcagcttctcttcctcctgctactctggctcccagataccaccggagaaattgtgttgacacagtctccagccaccctgtctttgtctccaggcgaaagagccaccctctcctgccgagcaagtgagaatgtttacagctacttagcctggtaccaacagaaacctggccaggctcctaggctcctcatctattttgcaaaaaccttagcagaagggattccagccagattcagtggcagtggttccgggacagacttcactctcaccatcagcagcctagagcctgaagattttgcagtttattactgtcaacatcattccgataatccgtggacattcggccaagggaccaaggtggaaatcaaaggtggcggtggctcgggcggtggtggatctggaggaggtgggagcggaggaggagctagcgaggtgcagctggtgcagtctggagcagaggtgaaaaagcccggagagtctctgaagatttcctgtaagggatccggttactcattcactggctacaatatgaactgggtgcgccagatgcccgggaaaggcctcgaatggatgggcaatattgatccttattatggtggtactacctacaaccggaagttcaagggccaggtcactatctccgccgacaagtccatcagcaccgcctacctgcaaggagcagcctgaaggcctcggacaccgccatgtattactgtgcacgctcagtcggccctttcgactcctggggccagggcaccctggtcactgtctcgagttgtccaccgtgcccagcacctgaactcctgggtggaccgtcagtcttcctcttccccccaaaacccaaggacaccctcatgatctcccggacccctgaggtcacatgcgtggtggtggacgtgagccacgaagaccctgaggtcaagttcaactggtacgtggacggcgtggaggtgcataatgccaagacaaagccgcgggaggagcagtacaacagcacgtaccgtgtggtcagcgtcctcaccgtcctgcaccaggactggctgaatggcaaggagtacaagtgcaaggtctccaacaaagccctcccagcccccatcgagaaaaccatctccaaagccaaagggcagccccgagaaccacaggtgtacaccctgcccccatcccgggatgagctgaccaagaaccaggtcagcctgacctgcctggtcaaaggcttctatccaagcgacatcgccgtggagtgggagagcaatgggcagccggagaacaactacaagaccacgcctcccgtgctggactccgacggctccttcttcctctacagcaagctcaccgtggacaagagcaggtggcagcaggggaacgtcttctcatgctccgtgatgcatgaggctctgcacaaccactacacgcagaagagcctctccctgtctccgggtaaatg actc taga 01905184 MEAPAQILLFLILLWLPDTTGEIVLTQSPATLSLSPGERATLSCRASENVYSYLAWYQQKPGQAPRLLIYFAKTLAEGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQHHSDNPWTFGQGTKVEIKGGGGSGGGGSGGGGSGGGASEVQLVQSGAEVKKPGESLKISCKGSGYSFTGYNMNWVRQMPGKGLEWMGNIDPYYGGTTYNRKFKGQVTISADKSISTAYLQWSSLKASDTAMYYCARSVGPFDSWGQGTLVTVSS CPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG K 019008 85aagcttgccgccatggaagccccagctcagcttctcttcctcctgctactctggctcccagataccaccggagaaattgtgttgacacagtctccagccaccctgtctttgtctccaggcgaaagagccaccctctcctgccgaacaagtgaaaatgtttacagctacttagcctggtaccaacagaaacctggccaggctcctaggctcctcatctattttgcaaaaaccttagcagaaggaattccagccaggttcagtggcagtggatccgggacagacttcactctcaccatcagcagcctagagcctgaagattttgcagtttattactgtcaacatcattccgataatccgtggacattcggccaagggaccaaggtggaaatcaaaggtggcggtggctcgggcggtggtggatctggaggaggtgggaccggtgaggtgcagctggtgcagtctggagcagaggtgaaaaagcccggagagtctctgaagatttcctgtaagggatccggttactcattcactggctacaatatgaactgggtgcgccagatgcccgggaaaggcctggagtggatgggcaatattgatccttattatggtggtactacctacaaccggaagttcaagggccaggtcactatctccgccgacaagtccatcagcaccgcctacctgcaatggagcagcctgaaggcctcggacaccgccatgtattactgtgcacgctcagtcggccctatggactactggggccgcggcaccctggtcactgtctcctagatcaggagcccaaatcttctgacaaaactcacacatctccaccgtgcccagcacctgaactcctgggtggaccgtcagtcttcctcttccccccaaaacccaaggacaccctcatgatctcccggacccctgaggtcacatgcgtggtggtggacgtgagccacgaagaccctgaggtcaagttcaactggtacgtggacggcgtggaggtgcataatgccaagacaaagccgcgggaggagcagtacaacagcacgtaccgtgtggtcagcgtcctcaccgtcctgcaccaggactggctgaatggcaaggagtacaagtgcaaggtctccaacaaagccctcccagcccccatcgagaaaaccatctccaaagccaaagggcagccccgagaaccacaggtgtacacctgcccccatcccgggatgagctgaccaagaaccaggtcagcctgacctgcctggtcaaaggcttctatccaagcgacatcgccgtggagtgggagagcaatgggcagccggagaacaactacaagaccacgcctcccgtgctggactccgacggctccttcttcctctacagcaagctcaccgtggacaagagcaggtggcagcaggggaacgtcttctcatgctccgtgatgcatgaggctctgcacaaccactacacgcagaagagc ctctccctgtctccgggtaaatga 019008 86MEAPAQLLFLLLLWLPDTTGEIVLTQSPATLSLSPGERATLSCRTSENVYSYLAWYQQKPGQAPRLLIYFAKTLAEGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQHHSDNPWTFGQGTKVEIKGGGGSGGGGSGGGGASEVQLVQSGAEVKKPGESLKISCKGSGYSFTGYNMNWVRQMPGKGLEWMGNIDPYYGGTTYNRKFKGQVTISADKSISTAYLQWSSLKASDTAMYYCARSVGPMDYWGRGTLVTVSSDQEPKSSDKTHTSPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSP GK 019009 87aagcttgccgccatggaagccccagctcagcttctcttcctcctgctactctggctcccagataccaccggtgaaattgtgttgacacagtctccagccaccctgtctttgtctccaggcgaaagagccaccctctcctgccgaacaagtgaaaatgtttacagctacttagcctggtaccaacagaaacctggccaggctcctaggctcctcatctattttgcaaaaacettagcagaaggaattccagccaggttcagtggcagtggatccgggacagacttcactctcaccatcagcagcctagagcctgaagattttgcagtttattactgtcaacatcattccgataatccgtggacattcggccaagggaccaaggtggaaatcaaaggtggcggtggctcgggcggtggtggatctggaggaggtggggctagcgaggtgcagctggtgcagtctggagcagaggtgaaaaagcccggagagtctctgaggatttcctgtaagggatccggttactcatteactggctacaatatgaactgggtgcgccagatgcccgggaaaggcctggagtggatgggcaatattgatccttattatggtggtactacctacaaccggaagttcaagggccaggtcactatctccgccgacaagtccatcagcaccgcctacctgcaatggagcagcctgaaggcctcggacaccgccatgtattactgtgcacgctcagtcggccctatggactactggggccgcggcaccctggtcactgtctcctctgatcaggagcccaaatcttctgacaaaactcacacatctccaccgtgcccagcacctgaactcctgggtggaccgtcagtcttcctcttccccccaaaacccaaggacaccctcatgatctcccggacccctgaggtcacatgcgtggtggtggacgtgagccacgaagaccctgaggtcaagttcaactggtacgtggacggcgtggaggtgcataatgccaagacaaagccgcgggaggagcagtacaacagcacgtaccgtgtggtcagcgtcctcaccgtcctgcaccaggactggctgaatggcaaggagtacaagtgcaaggtctccaacaaagccctcccagcccccatcgagaaaaccatctccaaagccaaagggcagccccgagaaccacaggtgtacaccctgcccccatcccgggatgagctgaccaagaaccaggtcagcctgacctgcctggtcaaaggcttctatccaagcgacatcgccgtggagtgggagagcaatgggcagccggagaacaactacaagaccacgcctcccgtgctggactccgacggctccttcttcctctacagcaagctcaccgtggacaagagcaggtggcagcaggggaacgtcttctcatgctccgtgatgcatgaggctctgcacaaccactacacgcagaagagcctctccctgtctccgggt aaatga 019009 88MEAPAQLLFLLLLWLPDTTGEIVLTQSPATLSLSPGERATLSCRTSENVYSYLAWYQQKPGQAPRLLIYFAKTLAEGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQHHSDNPWTFGQGTKVEIKGGGGSGGGGSGGGGASEVQLVQSGAEVKKPGESLRISCKGSGYSFTGYNMNWVRQMPGKGLEWMGNIDPYYGGTTYNRKFKGQVTISADKSISTAYLQWSSLKASDTAMYYCARSVGPMDYWGRGTLVTVSSDQEPKSSDKTHTSPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSP GK

1. A composition comprising a CD37-specific binding protein and aCD20-specific binding protein.
 2. The composition of claim 1, whereinthe CD37-specific binding protein is derived from G28-1, and wherein theCD37-specific binding protein comprises a light chain CDR1, CDR2, andCDR3 and heavy chain CDR1, CDR2, and CDR3, wherein said heavy chain CDR3comprises the amino acid sequence of SEQ ID NO: 67, 68, or 69, andwherein said CD37-specific binding protein binds CD37.
 3. Thecomposition of claim 1, wherein the CD37-specific binding protein is afusion protein comprising a CD37-specific binding domain polypeptide anda region derived from a constant region of an immunoglobulin.
 4. Thecomposition of claim 1, wherein the CD37-specific binding protein sharesthe same or an overlapping epitope with G28-1.
 5. The composition ofclaim 1, wherein the CD37-specific binding protein comprises, from aminoto carboxy terminus, an scFv, a human immunoglobulin hinge region, andhuman immunoglobulin CH2 and CH3 domains.
 6. The composition of claim 1,wherein the CD37-specific binding protein is not linked to aradioisotope.
 7. The composition of claim 1, wherein the CD20-specificbinding protein is rituximab.
 8. A method for treating a disease ordisorder associated with aberrant B cell activity, the method comprisingadministering to a subject in need thereof an effective amount of thecomposition of claim 1, wherein the composition has a synergistic effectin the treatment of the disease or disorder.
 9. A method for treating adisease or disorder associated with aberrant B cell activity, the methodcomprising administering to a subject in need thereof an effectiveamount of a CD37-specific binding protein in combination with aCD20-specific binding protein, wherein the combination treatment has asynergistic effect in the treatment of the disease or disorder.
 10. Themethod of claim 9, wherein the CD37-specific binding protein is derivedfrom G28-1, and wherein the CD37-specific binding protein comprises asingle chain polypeptide with light chain CDR1, CDR2, and CDR3 and heavychain CDR1, CDR2, and CDR3, wherein said heavy chain CDR3 comprises theamino acid sequence of SEQ ID NO: 67 or 68, and wherein saidCD37-specific binding protein binds CD37.
 11. The method of claim 9,wherein the CD37-specific binding protein is a fusion protein comprisinga CD37-specific binding domain polypeptide and a region derived from aconstant region of an immunoglobulin.
 12. The method of claim 9, whereinthe CD37-specific binding protein shares the same or an overlappingepitope with G28-1.
 13. The method of claim 9, wherein the CD37-specificbinding protein comprises, from amino to carboxy terminus, an scFv, ahuman immunoglobulin hinge region, and human immunoglobulin CH2 and CH3domains.
 14. The method of claim 9, wherein the anti-CD37-specificbinding protein comprises an amino acid sequence selected from the groupconsisting of: SEQ ID NO: 2, 6, 48, and
 52. 15. The method of claim 9,wherein the CD37-specific binding protein is not linked to aradioisotope.
 16. The method of claim 9, wherein the CD20-specificbinding protein is rituximab.
 17. The method of claim 8 or 9, whereinthe disease or disorder is a B cell cancer or an autoimmune disease. 18.The method of claim 17, wherein the B cell cancer is selected from thegroup consisting of Hodgkin's disease, non-Hodgkins lymphoma (NHL) orcentral nervous system lymphomas], leukemias [such as acutelymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CLL), Hairycell leukemia and chronic myoblastic leukemia], myelomas (such asmultiple myeloma), small lymphocytic lymphoma, B-cell prolymphocyticleukemia, lymphoplasmacytic lymphoma, splenic marginal zone lymphoma,plasma cell myeloma, solitary plasmacytoma of bone, extraosseousplasmacytoma, extranodal marginal zone B-cell lymphoma ofmucosa-associated (MALT) lymphoid tissue, nodal marginal zone B-celllymphoma, follicular lymphoma, mantle cell lymphoma, diffuse large8-cellymphoma, mediastinal (thymic) large B-cell lymphoma, intravascularlarge B-cell lymphoma, primary effusion lymphoma, Burkittlymphoma/leukemia, B-cell proliferations of uncertain malignantpotential, lymphomatoid granulomatosis, and post-transplantlymphoproliferative disorder.
 19. The method of claim 17, wherein theautoimmune disease is selected from the group consisting of rheumatoidarthritis, multiple sclerosis, systemic lupus erythematosus, Crohn'sdisease, Sjogren's syndrome, Grave's disease, type I diabetes mellitus,psoriasis, immune thrombocytopenic purpura, pemphigus, idiopathicinflammatory myopathy, myasthenis gravis, and Waldenstorm'smacroglobinemia.
 20. A method for inducing complement-dependentcytoxicity in B cells comprising contacting B cells with a CD37-specificbinding protein in combination with a CD20-specific binding protein. 21.A method for inducing ADCC in B cells comprising contacting B cells witha CD37-specific binding protein in combination with a CD20-specificbinding protein.
 22. A method for inducing apoptosis in cells comprisingcontacting B cells with a CD37-specific binding protein in combinationwith a CD20-specific binding protein.